2019, 20(3):485-495. DOI: 10.13430/j.cnki.jpgr.20181211002
Abstract:Oat is a nutrient-rich food for both human and livestock feed. In order to meet the increasing demands by the development of Oat industry,modern Oat breeding requires the combination of modern molecular biology technology and traditional breeding methods. This article reviews world-wide main achievements and challenges in Oat genetics and breeding programs such as construction of genetic linkage map, QTL identification, genomic selection, and genetic engineering breeding. Meanwhile, the current problems and prospects of the application of molecular breeding in Oat are discussed. Thus, we hope that this review will help to find potential strategies of oat improvement and future perspectives for Oat breeding.
2019, 20(3):496-507. DOI: 10.13430/j.cnki.jpgr.20180801003
Abstract:Sorghum[Sorghum bicolor(L.) Moench] is one of the globally most important crops that can be used for grain, feed, fiber and energy. Because of its developed root system, thick leaf waxy layer, strong osmotic adjustment ability and high photosynthetic efficiency, sorghum showed strong adaptability particularly under drought conditions, in order to meet the global climate change, water scarcity and world food demand. As drought is one of the major adverse factors that restrict the agricultural production in the world, how to solve the problem of sorghum yield under drought is still a great challenge for the breeders. In order to provide reference for the selection of new varieties of sorghum drought resistance, here we review the methods for drought resistance, drought indexes and excellent germplasm resources of sorghum, as well as the research progress on QTL mapping of drought resistance and drought resistance related charactering sorghum. Finally, we provide the prospective in studies for sorghum drought resistance, including: (1) Large-scale tests for drought resistance in sorghum germplasm resources for entire growth period, (2) Gene mining using next-generation sequencing technology, (3) updated breeding methodologies using genetic modification and gene editing.
2019, 20(3):508-520. DOI: 10.13430/j.cnki.jpgr.20180810002
Abstract:Bromeliaceae is one of the morphologically and ecologically diverse flowering plant families, which originally distributed in the tropics and subtropics of the New World. Their beautiful shapes and colors, low maintenance and easy adaptability have brought bromeliads into worldwide as ornamental plants. In this review, the achievements in taxonomy, conservation and utilization of Bromeliaceae germplasm resourses, breeding and genetics, and the new techniques in its breeding were collected and analyzed. To date, hybridization is still the main breeding approach for germplasm innovation in ornamental bromeliads. The breeding objectives that Colorful bracts, varied inflorescence shapes, spineless leaves, moderate plant type, early flowering, and excellent cold resistance are pursued by breeders. Strong prefertilization barriers were observed after intraspecific, interspecific and intergeneric crosses, but only minor postfertilization difficulties occurred in Bromeliaceae. To overcome these prefertilization barriers cut style and grafted style pollination techniques can be used to increase the percentage of fertilization. The parentage of most actual hybrids in commerce is very complex, and hybridization results are unpredictable. It is suggested that polyploid breeding and molecular breeding should be strengthened in the near future.
2019, 20(3):521-529. DOI: 10.13430/j.cnki.jpgr.20180831001
Abstract:Southern corn rust has become an economically important disease that affects maize yield in China. To explore new genetic resources for resistance to southern rust, we developed F1 hybrids and F2 population by a cross between a highly resistant inbred line W456 and susceptible Huangzaosi. These genetic materials were subjected for genetic analysis and QTL mapping of resistance genes. A framework of linkage map comprising 200 SSR markers was constructed which expands 3331 cM of the maize genome with an average marker interval of 16.6 cM. QTL mapping for resistance was conducted using software IciMapping V4.1 package for inclusive composite interval mapping. As a result, six QTLs including qSCR3, qSCR7, qSCR8-1, qSCR8-2, qSCR9 and qSCR10, were detected on chromosomes 3, 7, 8, 9 and 10, which were flanked by markers umc2105 and umc1729, umc1066 and bnlg2271, umc1904 and umc1984, umc1984 and bnlg1651, umc1957 and bnlg1401, and umc2034 and umc1291, respectively. The phenotypic variance explained (PVE) ranged from 2.61% to 24.19%, explaining 62.3% of the total phenotypic variation. Notably, qSCR10 on chromosome 10 accounted for 24.19% of the phenotypic variation, thus being a major QTL responsible for resistance to southern rust in maize. Moreover, this resistance locus was further delimited by new flanking markers to a 2.51 cM genetic interval. Thus, this work accomplished the preliminary mapping of resistance loci, which might be valuable in breeding for resistant varieties against Southern corn rust.
2019, 20(3):530-537. DOI: 10.13430/j.cnki.jpgr.20180828003
Abstract:The seed production potential of male sterile lines is the main factor affecting hybrid seed productivity. The lack of early selection method always leads to low hybrid seed yield and unsuitable for application. A collection of radish landraces with high quality have been developed in China over decades, but nowadays these germplasms showed characterization declining, cultivation area reducing and scattering. Hybrid breeding is an effective way to improve the agronomic quality, maintain the cultivation area and expand the planting region of the landraces. By hybridization using the Ogura cytoplasm with 26 radish landraces, 16 introgression lines were absolute or near absolute male sterile. A osmia pollination and nylon mesh isolation method were used to test the seed production potential of the male sterile and maintainer lines of these 16 landraces. The two accessions, Lian-si and May-Red, showed high silique yield in both male sterile and maintainer plants, with the potential of developing high-seed-yielding male sterile lines. The Red-lanterns, Big-green-skin and Beautiful-in-heart contain high silique yield plants in male sterile lines while all maintainer plants showed low yield. Improving the seed productivity of maintainer lines are needed for these three landraces. The Little-red-robe summer radish and Fu-gou radish produced medium quantity of siliques from both male sterile and maintainer plants, have application potential if substantial selection can improve the seed yield. The Red summer radish, Green crisp and three other landraces were proved not suitable to produce hybrid seeds use Ogura-CMS due to low yield. The Dog-Canister, Jiang-xian-white and Ivory were identified as self incompatibility materials. This study revealed that the seed yield are differing significantly among varieties and single plants, indicating a necessary of selecting the high-yielding plant descendants with generations. Thus, this worked reported a simple and efficient method for screening the seed production potential, which finally resulted in generation of seven Ogura-CMS radishes with high seed yielding potential .
2019, 20(3):538-549. DOI: 10.13430/j.cnki.jpgr.20180826001
Abstract:Potato is an important crop in mountainous areas of China, such as Chongqing. Late blight (LB) caused by Phytophthora infestans has been a major threat to sustainable potato production in China. Growing disease-resistant varieties is the most economical, effective and environmentally friendly way to control LB in potato production. In order to understand the composition of resistance (R) genes to late blight from different germplasms and to obtain potato varieties (lines) with resistance to LB in Chongqing, screening of R genes using molecular marker linked to LB and evaluation of LB resistance upon natural and artificial inoculations were carried out in 218 potato varieties (lines) from different regions. The results showed that six R genes were detected in the tested genotypes and the composition of the molecular markers could mainly be divided into four types, including Type I, which was characterized by the presence of a broad-spectrum resistance gene RB; Type III, which was characterized by the absence of R2 family markers, most of which were susceptible to late blight; Type II and IV, which were characterized by three R genes (R2 Family+R3a+R3b) and four R genes (R1+R2 Family+R3a+R3b) marker types, respectively, which showed a certain proportion of LB resistance in these two types. The proportion of resistance in type IV was higher than that in type II. These results suggested that genotypes containing RB gene markers positively contributed to LB resistance. Screening of these gene markers will help to improve the breeding efficiency of LB resistance in Chongqing. By analyzingR genes compositions of and LB resistance tests in 218 potato genotypes, this study provided scientific basis for the future popularization and application of new varieties (lines) and resistance breeding in Chongqing, and also provided genetic resources for the discovery of new R genes.
2019, 20(3):550-555. DOI: 10.13430/j.cnki.jpgr.20181017001
Abstract:In order to determine the resistance difference of sorghum germplasm and the pathogenicity difference of Sarocladium strictum from sorghum and maize, a total of 110 sorghum germplasm accessions were subjected for evaluation for the resistance to Black Bundle Disease under artificial inoculation conditions from 2016 to 2017. With this collection, 13 lines (11.8%) were scored as immune (IM), 17 lines (15.5%) were highly resistant (HR), 14 lines (12.7%) were resistant (R) and 14 lines (12.7%) were moderately resistant (MR), 17 lines (15.5%) were susceptible (S), 35 lines (31.8%) were highly susceptible (HS) to GHS-1. Twenty-one lines (19.1%) were immune (IM), 11 lines (10.0%) were highly resistance (HR), 15 lines (13.6%) were resistance (R), 12 lines (10.9%) were moderately resistance (MR), 21 lines (19.1%) were susceptibility (S) and 30 lines (27.3%) with highly susceptibility (HS) to YHS-1. These results showed that a proportion of restorer lines widely used in sorghum breeding were resistant to Black Bundle Disease, and the pathogenicity of Black Bundle Disease pathogens isolated from sorghum and maize was different.
2019, 20(3):556-563. DOI: 10.13430/j.cnki.jpgr.20180817001
Abstract:This study attempted to identify the seedling drought resistance of RILs population from an indica and japonica crossing lines. A population of 120 recombinant inbred lines (RILs), which were derived from a cross between an elite indica cultivar IR29 and a drought-resistant japonica line ZD15, were used. An artificial drought stress was mimicked by PEG-6000 treatment. These parameters including the germ length and coleoptile length at germination stage, as well as the root length, root-shoot ratio, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight at seedling stage, were measured. With the principal component analysis and membership function method, an objective comprehensive evaluation value (D value) of drought resistance was obtained. According to the D value, the 122 rice lines (or variety) were divided into three groups. The groupⅠcontaining 33 lines with D value between 0.201 and 0.400, was a drought sensitive group. The groupⅡcontaining79 lines with D value between 0.401 and 0.600, was a moderate drought resistant group. The last group containing 10 lines with D value between 0.601 and 0.800, was a drought resistant group. Using stepwise regression and principal component analysis, these eight traits were selected to be evaluation indicators for drought resistance at seedling stage of rice. Taken together, the drought-resistant lines selected in this study can be further cultivated as breeding intermediate materials, or used as breeding resources to enrich the rice breeding resource in Ningxia.
2019, 20(3):564-573. DOI: 10.13430/j.cnki.jpgr.20180815001
Abstract:In this paper, 44 colored barley germplasms were used as test materials to comprehensively evaluate the multi-index salt tolerance of colored barley germplasm., The germination potential, germination rate, germination index and germination vigor index of the experimental seeds were determined by combining the two color indicators YU (color brightness and concentration) to identify the salt tolerance of the bud stage, and correlation analysis and principal component analysis were used , cluster analysis and other methods to carry out this test. The results showed that the germination rate and germination index were the most sensitive to salt stress response, and germination length and root length are slower to respond to salt stress, and the color brightness and salt tolerance were negatively correlated. The color concentration and salt tolerance were significantly positively correlated. Correlation analysis using F value shows that a positive correlation between the grain color and the salt tolerance, the deeper the color, the stronger the salt tolerance; 44 kinds of colored barley can be divided into 4 categories by comprehensive index F value: (i) four accessions, such as XZDM-1401, XZDM-1404, XZDM-1543, XZDM-1546, which showed strong salt-tolerant; (ii) 16 accessions, such as ZDM-926, XZDM-957, XZDM-972, that showed moderate salt tolerant; (iii) 12 accessions, such as XZDM-815, XZDM-1606 and XZDM-972, that showed weak salt tolerant; (iv) 12 accessions, such as XZDM-973, XZDM-1042 and XZDM-1318, that showed highly salt sensitive.
2019, 20(3):574-582. DOI: 10.13430/j.cnki.jpgr.20180908002
Abstract:Potato is considered to be sensitive to drought due to its shallow root system. Currently, only few potato varieties with high drought tolerance were released, because of the narrow genetic base that restricts the breeding for drought tolerance. Employment of exotic potato resource might be alternative strategy to accelerate the breeding for new varieties with high drought resistance. 316 advanced clones and 3 cultivated varieties were evaluated with augmented block design compared to 5 local varieties under drip irrigation and rainfed condition in 2016 and 2017. AMMI and GGE model were used to analyze the effects of genotype (G) and environment (E) on yield and combine with drought index to identify the yield potential and stability of each genotype. Under rainfed condition, the average potato yield was similar but the coefficient variation had large difference between the two years, while under drip irrigation, the two variables showed opposite. Potato yield was affected by G, E and G by E interaction significantly, of which the sum square accounted for 43.39, 39.36 and 17.26% of total sum square. Genotypes C93 and YS902 showed highest drought tolerance in both years followed by genotype C48. Genotypes C93, YS902 and C48 could be as parent for drought breeding. Taken together, the genotypes with drought tolerance might serve as elite parental lines, which become of interest in basic and applied resources.
2019, 20(3):583-597. DOI: 10.13430/j.cnki.jpgr.20181008003
Abstract:By identifying the ability of drought resistance and screening indices at flowering and boll setting stage of upland cotton(Gossypium hirsutum L.), this study aimed to provide the materials and a theoretical basis for drought-resistant breeding and cultivation. 153 varieties (lines) were planted under normal irrigation and drought stress conditions, while the drought treatment was conducted by using reduced water at flowering and boll setting stage. Several agronomical traits, including means of plant height, lint percentage, single boll weight, the first node of fruit branch, initial internodes of fruiting branch, effective boll number, fruit branch number, cotton seed yield, fiber length (mm), specific breaking length, uniformity and micronaire, were measured. The statistical analysis was conducted by combination with the comprehensive drought coefficient, membership function, principal component analysis, association analysis and clustering analysis. The agronomic traits of upland cotton varieties (lines) represented large variation upon drought stress treatment. The ranks of drought resistance of tested upland cotton varieties (lines) based on D value. According to clustering results of D value, these upland cotton varieties (lines) could be divided into five types. Type 1(Strongly resistant) included 5 cotton varieties, type 2(Resistant) had 35 cotton varieties, type 3(Modetarely resistant) had 57 cotton varieties, type 4(Modetarely sensitive) had 56 cotton varieties and type 5(Sensitive) had 1 cotton variety. The yield of tested upland cotton varieties (lines) had significant and positive correlation with D (drought resistance comprehensive evaluation) value, CDC (comprehensive drought resistance coefficient) value and WDC (weight drought resistance coefficient) value. Finally, we identified two varieties Israel 1101 and yanzao 2, which were identified as drought resistant and sensitive upland cotton varieties at flowering and boll setting stage, respectively. Plant height, yield, single boll weight, effective boll number and height of the first branch could be used as the identification indices for drought resistance in upland cotton germplasm resources at flowering and boll setting stage.
2019, 20(3):598-609. DOI: 10.13430/j.cnki.jpgr.20180901001
Abstract:In order to screen the drought resistance identification index and the drought-resistant alfalfa germplasm materials, and provide the theory and basic materials for the breeding of new drought-resistant varieties. In this study, we investigated the changes of root length, bud length, germination potential, germination rate, germination index, vitality index and root bud ratio of 59 alfalfa germplasms with different drought resistance that are from different region under drought stress condition, which was stimulated by using two treatments including distilled water and -0.6MPa PEG-6000 water solution. Correlation analysis, subordinate function coefficients, comprehensive drought resistance coefficient, grey relational analysis, stepwise regression and clustering analysis were used to evaluate the drought resistance and select evaluation indices in tested alfalfa cultivars during the germination period. The results showed that drought stress had significant effects on all indexes at the germination stage. By employment of this approach, we obtained three alfalfa genotypes, including Caoyuan NO.3, Sidey7 and WL903, which showed strong drought-resistant at the germination stage. These germplasms were selected as the research material for drought resistance breeding and drought resistance mechanism. Notably, root length, germination rate and vitality index were more sensitive than other indicators and could be used as a priority indicator for drought resistance identification and breeding of drought-resistant varieties. The results also showed that it is reasonable and accurate to use the comprehensive evaluation method with D value as the main index and WDC value as the auxiliary index in alfalfa to carry out comprehensive evaluation of drought resistance and screening of evaluation indicators.
2019, 20(3):610-623. DOI: 10.13430/j.cnki.jpgr.20180822001
Abstract:Basic-cross is an approach mainly used for germplasm enhancement, which served as the basis and premise in sugarcane breeding. To establish a normative drought resistance identification system for Yunrui sugarcane parents and evaluate new blood parents from basic-crosses for drought resistance, thirty-six Yunrui sugarcane parents from basic-crossing were used as materials treated by artificial water stress, including normal water supply (as control) and water stress. Twelve indices including PMP, contents of MDA, PRO, chlorophyll fluoresence and other parameters were measured. Then drought resistance coefficient (DC), comprehensive drought resistance coefficient (CDC), drought resistance comprehensive evaluation value (D), weight drought resistance coefficient (WDC), subordinate function analysis, principal component analysis, clustering analysis, grey relational analysis and stepwise regression analysis were applied to identify the drought resistance level and screen its closely related indices. Firstly, the results indicated that moisture stress had significant effects on all indices at p value 0.0001, which suggested that drought stress was proper and all the indices selected were sensitive to drought. Secondly, the principal component analysis results revealed that seven principal components could represent 89.2686% of the original data information of sugarcane parents drought resistance. These factors could be divided into three groups and named photosynthesis factor, moisture utilization factor and physiological regulation factor. Thirdly, The clustering analysis results showed that thirty-six tested materials could be divided into five groups including high resistance to drought (groupⅠ), moderately high resistance to drought (groupⅡ), moderate resistance to drought (group Ⅲ), each accounting for 25% respectively, low resistance to drought (group Ⅳ) accounting for 13.9% and sensitive to drought (group Ⅴ) accounting for 11.1%. Nine elite materials Yunrui14-195, Yunrui15-88, Yunrui11-98, Yunrui11-256, Yunrui15-158, Yunrui14-78, Yunrui13-26, Yunrui12-137 and Yunrui15-73 were identified to have high resistance to drought. The grey relational analysis and stepwise regression analysis results further confirmed PMP, MDA, PRO and the proportion of free water and bound water were the key resistance indices with close correlation to drought, which could efficiently improve sugarcane drought resistance evaluation work. Thus, the established approach might become useful in large-scale screening for drought resistant sugarcane resources.
2019, 20(3):624-633. DOI: 10.13430/j.cnki.jpgr.20180924002
Abstract:Yunnan Saccharum spontaneum L serves as valuable wild germplasm resource can be used in sugarcane breeding. The quantitative characters of 68 BC1F2 Yunnan Saccharum spontaneum L were investigated using the principal of numerical classification, and the PCA (define) of 10 quantitative characters were analyzed. Scatter plot was drawn based on the first 3 principal components (PC) and clustering analysis was carried out based on the genetic coefficients. The results showed that the coefficient variation of the quantitative characters ranged from 10.57% to 35.30%. The theoretical sugar content and yield in November had a high coefficient of variation over 30%, indicating a high variation potential. Principle component analysis indicated that the first 3 PC accounted for 80.83% of variation among the materials, followed by single stem weight yield factor, brix sugar factor and cluster effective stem sugar yield factor. These 68 innovative materials could be divided into 4 categories at D=10.00. Each group had different characteristics, which could be referred for castor breeding with different purposes. The scatter plot of the former three principal components indicated the coefficients of the first three PCs were higher in YGF211-50, YGF211-56, YGF211-40, YGF211-66, YGF211-77, YGF211-10, YGF211-19, YGF211-85, YGF211-45, YGF211-37, YGF211-25, YGF211-23, YGF211-18, and these accessions could be used in the breeding.
2019, 20(3):634-645. DOI: 10.13430/j.cnki.jpgr.20181014001
Abstract:Heading date is an important character, which determines the region and season adaptability of crops. Making clear the suitable planting regions for different foxtail millet cultivars is very important to production practice. 160 foxtail millet resources were investigated for nine traits (e.g. heading date, plant height, panicle length, panicle weight and so on) at Hainan, Luoyang and Jilin in two consecutive years. Correlation analysis showed that a negative correlation was existed between heading date and 1000-grain weight across three regions, but a positive correlation was existed between heading date and plant height, leaf number, panicle length, panicle diameter, panicle weight, branch number per panicle and grain weight per panicle at Hainan and Luoyang, a minor negative correlation was existed between heading date and grain weight per panicle at Jilin, which indicated that with the proper delay of heading date, the grain yield of foxtail millet could be increased by grain number increasement, while excessive delay of heading date might lead to decline of production potential. Variance analysis showed that heading date had significant effect on plant height, leaf number, panicle length, panicle diameter, panicle weight, branch number per panicle, grain weight per panicle and 1000-grain weight (P<0.05) across three regions. At Hainan, with the delay of heading date, grain weight per panicle gave an increasing trend. The cultivars with their heading date longer than 40d possesed the largest grain weight per panicle. At Luoyang, the cultivars with their heading date ranged from 50d to 60d possesed the highest grain weight per panicle. At Jilin, the cultivars with their heading date ranged from 70d to 80d possesed the highest grain weight per panicle. The average grain weight per panicle of each variety across three regions was measured and based on which 53 broad ecological adaptability foxtail millet varieties were screened out. The optimum regression equations between plant height, leaf number, branch number per panicle and heading date were established across three regions. This study concluded that within a certain heading date range, the yield of foxtail millet was increased by increasing grain number but not 1000-grain weight. The selected broad ecological adaptability resources and the established regression equations provided foundation for broad-adaptability cultivar breeding and accurately selection of plant height, leaf number and branch number per panicle by heading date information.
2019, 20(3):646-653. DOI: 10.13430/j.cnki.jpgr.20181210001
Abstract:Buckwheat (Fagopyrum ssp.) is an ancient crop belonging to Fagopyrum Mill, Polygonaceae family, which has been widely cultivated around the world, especially in East Asia and East Europe. Buckwheat is the major food crop in the high-attitude regions, including the Liangshan region of China for thousands of years. Buckwheat is rich in nutrition and considered as a functional food for the high contents of rutin and other bioactive compounds that are antioxidant and anti-tumor. Two species of cultivated buckwheat, common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum), are widely spread, while the wild buckwheat resources only distribute in some certain regions. Southwest China, including Sichuan, Yunnan, Guizhou Province and Tibet Autonomous Region, is widely known as the center of origin, distribution and diversity of wild buckwheat plants. So far, more than 20 buckwheat species have been named and classified, most of which have been found in Southwest China. The extremely complicated geographical environment of this area renders a number of diversified wild buckwheat resources. However, the scientific classification of Fagopyrum Mill species is deficient, and some wild species are synonyms. Since 2004, our research team continually made field investigation and specimens collection works in Southwest China, anatomic observation of flowers and fruits were also made in our lab. Based on these morphological data as well as buckwheat chromosome number detecting results, comparing with other specimens, model photos and pervious articles, the Fagopyrum Mill was taxonomic revised and the number of species were adjusted from 28 to 21, namely, Fagopyrum megaspartanium Q. F. Chen and F. pilus Q. F. Chen were treated as synonyms of F. cymosum (Trrev)Meisn; F. pleioramosum Ohnishi and F. wenchuanense J.R.Shao were treated as synonyms of F. caudatum (Samuelsson) A. J. Li; F. callianthum Ohnishi was treated as a synonym of F. qiangcai D.Q.Bai; F. zuogongense Q.F.Chen was treated as a synonym of F. homotropicum Ohnishi; F. longzhoushanense J.R.Shao was treated as a synonym of F. pugense T.Yu. The key to species of Fagopyrum were also revised and presented. Our results provided a better understanding of the evolution position of Fagopyrum Mill and built a framework to learn the genetic relationships between buckwheat species.
2019, 20(3):654-661. DOI: 10.13430/j.cnki.jpgr.20180828001
Abstract:From November of 2015 to Jul of 2018, as a sub-project of the Third National Survey and Collection Action on Crop Gemplasm Resources, we conducted a systematic investigation on the status quo and utilization of crop germplasm resources in Guangxi province, where 190 villages in 71 towns of 52 counties were surveyed. Through visiting and field surveying, a total of 308 maize (Zea mays L.) landraces were collected, among which the phenotypic variation of 270 maize landraces were identified and evaluated. Based on the collection sites, a number of landraces were found in North and Northwest of Guangxi, while fewer accessions were collected from the East and Southeast areas. Particularly, many of accessions were found from counties including Lingyun, Leye, Tianlin, Fengshang and Donglan.The results of vertical distribution showed that the distribution of maize landraces were most concentrated in the middle-high altitude(400~800m) mountain area, which accounted for 39.6% of the total collection.Preliminary identification results of agronomic characters showed that most of the collected maize accessions were waxy corn and white color. Notably, six maize landraces with elite traits were identified, including Mobai maize, Jiu jie huang, Pearl waxy corn, Xincheng white waxy corn, Longan popcorn and Tiandeng popcorn, which were excellent in stress ,diseases and insects resistance and had excellent performances in characters. Those special maize landraces would have a strong prospect for varieties utilization in quality, stress resistance, adaptability and nutrient efficient utilization.In this study,the classification and utilization value of the collected maize were evaluated.Local situation,growth and decline conditions of the maize landraces in the investigated area were analyzed.Besides,the protection and utilization of maize landraces in Guangxi were discussed.It provides a reference for the exploitation and innovative utilization of maize germplasm resources in Guangxi.
2019, 20(3):662-668. DOI: 10.13430/j.cnki.jpgr.20180903002
Abstract:The species of Chrysosplenium has significant pharmacological effects due to the flavonols component. In this study, a detailed field scientific expedition of Chrysosplenium germplasm resources in five provinces of China (Tibet, Yunnan, Sichuan, Qinghai, and Gansu) was performed. 19 species (including two varieties) and 145 specimens of Chrysosplenium were collected. In addition, two newly recorded species of Chrysosplenium (C. biondianum & C. qinlingense) were found in Sichuan province, and both were extensively found in China. Three new records were observed in Gansu province, including C. pilosum, C. lanuginosum and C. henryi. These specimens were preserved in the Herbarium of South-Central University for Nationalities (HSN). Thus, this work provided additional wild resources of Chrysosplenium in Tibetan-inhabited areas, which might be helpful in further classification of this genus.
2019, 20(3):669-676. DOI: 10.13430/j.cnki.jpgr.20181010001
Abstract:Taking advantage of the consulting and sorting relevant data of millet spicy resources, we carried out a field survey at 29 counties of 13 prefectures in Yunnan Province. 86 of millet spicy resources were obtained, including six types of yellow and white shells, shallow green shells, green shells, dark green shells, purple black shells and golden yellow shells. These accessions were over-represented at the low altitude regions, southern parts of Yunnan. The density gradually decreased with the elevation of altitude. For instance, the germplasms found at areas with low altitude and high temperature were small and fruity. The altitude of germplasms showed positive correlation with the fruit shape and pulp thickened, but negative correlation with the spicy flavor. Taken together, this study provided information and datasets for the classification, protection and development of Yunnan's millet spicy resources.
2019, 20(3):677-684. DOI: 10.13430/j.cnki.jpgr.20180902001
Abstract:Understanding the genetic diversity and population structure can effectively improve the breeding efficiency of grain sorghum new cultivar. In this study, genotyping by sequencing (GBS) technology was deployed to unlock the genetic diversity in a collection of 120 grain sorghum materials. Within 3456 SNP markers that were generated, the polymorphism information content (PIC) ranged from 0.013 to 0.574, with the average of 0.381, while SNP-based genetic distance value ranged from 0.137 to 0.538, with the average of 0.353. Both phylogenetic tree analysis and principal component analysis indicated that 120 grain sorghum genotypes were clustered into three groups. Group-1 was mainly composed of sorghum materials with a relatively distant relationship, including the USA material MN-3609. Within Group-2 and group-3, these genotypes were mainly collected from northern and south parts of China, respectively. Population structure analysis showed that the maximum ΔK was observed for K=3, suggested three sub-populations detected in 120 grain sorghum materials. This result was consistent with phylogenetic tree analysis and principal component analysis. Taken together, this resulted deciphered the genetic background and population structure of grain sorghum from the genotype diversity level, which will provide theoretical basis in breeding for grain-use sorghum new cultivar in China.
2019, 20(3):685-694. DOI: 10.13430/j.cnki.jpgr.20180924001
Abstract:This study analyzed the genetic diversity and indica-japonica gene frequencies of Jiangyong wild rice (Oryza rufipogon Griff.) populations, which were sampled in 1982, 2008 and 2017, using 39 SSR markers and 38 Indel markers respectively. The results showed that the genetic diversity of 40 accessions sampled and conserved in ex-situ in 1982 was higher than that in-situ conservation sampled in 2008 and 2017. No significant difference was observed in genetic diversity between the samples in 2008 and 2017. In addition, samples collected in different years displayed unobvious differentiation, with low genetic differentiation coefficient(Fst) and high gene flow(Nm). According to cluster analysis and principal coordinate analysis, we found that the genetic relationship between wild rice and japonica rice is closer than that between wild rice and indica rice. Most of the wild rice plants were grouped to japonica class, and a few belong to japonicaclinous class. In 2008, the percentage of japonicaclinous individuals increased by 10.0% compared with 1982, and in 2017, the percentage increased by 1.6% compared with 2008. These results implied that the indica gene frequency of wild rice increased with the environmental changes of in-situ conservation.
2019, 20(3):695-708. DOI: 10.13430/j.cnki.jpgr.20180927001
Abstract:To get insight of MYB genes in strawberry, we used bioinformatics methods to screen the MYB genes from the Fragaria vesca genome database, and further analyzed gene structure, conserved motif, chromosomal location, phylogenetic analysis and expression in the period of the development of anther. Our results showed that three types of MYB transcription factors, including 105 R2R3-MYB, 4 MYB3R, 1 MYB4R, were identified. These genes unevenly distributed on 7 chromosomes, e.g., that chromosome Fvb5 contained the largest number of 26 MYB genes. Some of MYBs formed distinct tandem duplicate gene clusters. Although the protein length of strawberry MYB genes differed, all of MYBs contained conserved R2R3 domain, with characteristic amino acids, especially orderly spaced conservative tryptophan residues (W). Phylogenetic and gene structure analysis showed that strawberry MYB genes were divided into 34 distinct groups (A1-A34). The function prediction of strawberry orthologous genes using Arabidopsis thaliana gene annotation showed strawberry MYB genes were most likely involved in flavone synthesis, cell fate, and biotic and abiotic stresses. Temporal or spatial expression trends of MYB genes during strawberry anther development indicated that FvMYB2, FvMYB85, FvMYB74, and FvMYB28 had increased expression during 5 period of the development of strawberry anther, which were mainly expressed in the later period of anther development. These results suggested that those MYB genes may play important role during strawberry anther development. Thus, this paper provided information for functional identification of strawberry MYB genes.
2019, 20(3):709-717. DOI: 10.13430/j.cnki.jpgr.20181015001
Abstract:MOC1 encodes for a plant-specific GRAS family protein, and this gene plays key role in the formation and development of axillary bud. Since the gene promoter is directly involved into transcriptional regulation, functional analysis can accurately locate the expression site, development stage and regulation mechanism of gene. Cloning the sequence and function analysis of ScMOC1 promoter will be of great significance in illustrating the regulation mechanism of ScMOC1. In this study, the 1874 bp promoter sequence upstream of ScMOC1 was isolated from the genomic DNA of sugarcane main cultivar ROC22 by using nested PCR and genomic walking methods. This isolated fragment was verified to be the promoter of ScMOC1 via sequence structure analysis. The results indicated that ScMOC1 promoter contained a few of core elements of the eukaryotic promoter such as TATA-box, CAAT-box, several light, hormone responsive elements and a cis-acting regulatory element related to meristem expression (CAT-box). We speculated that the ScMOC1 promoter could regulate the expression of ScMOC1 in a manner of hormone treatment, required for the sugarcane tillering regulation by the CAT-box cis-acting element. By constructing the target promoter into pBI121 plasmid that contains a GUS reporter, the results showed that this promoter could result in transient expression of GUS gene in sugarcane young leaves, and the deletion analysis indicated that the basic promoter sequence of the promoter was between 350 bp and 500 bp upstream of the starting codon ATG of ScMOC1. Thus, these results obtained above will provide the foundation information for ScMOC1 on transcriptional regulation.
2019, 20(3):718-727. DOI: 10.13430/j.cnki.jpgr.20180917001
Abstract:Abstract: The inheritance regularity of wild specific loci for Erianthus arundinacius and Saccharum spontaneum L. from intergeneric hybrid complex (E. arundinaceus × S. spontaneum) inheriting to generations was investigated, in order to provide theoretical basis for exploring new sugarcane parents. AFLP-PCR molecular markers combined with capillary electrophoresis were used to analyze the transmission dynamics of wild specific loci over generations and also clarify the genetic relationship among these materials. A total of 3695 loci were amplified from 29 AFLP primer combinations, with a polymorphic ratio of 97.89%. The genetic fragments derived from E. arundinacius and S. spontaneum were 43.96% and 56.04% respectively. The average heritability of E. arundinacius in F1, BC1 and BC2 were 8.25%, 1.9% and 0.63%, respectively, and the average heritability of S. spontaneum in F1, BC1 and BC2 was 16.98%, 2.4% and 0.21% respectively. Both indicated a reduction of foreign specific genetic loci over generations. By analyzing the ratios of sugarcane specific loci that remained in different generations, the genetic information of GT02-761 has been ranked first in F1. The average percentage of special loci for GT05-2743 inheriting to BC1 was 92.75%. The heritability for ROC23 inheriting to BC2 was the lowest, and the heritability for FN39 was the highest, up to 94.32%.The cluster analysis showed that the intergeneric hybrid complex was inherited more from male parent and the progeny from the intergeneric hybrid complex were inherited more from the sugarcane (Saccharum spp.), which was consistent with the analysis of molecular genetic relationship. The results showed that the genetic loci for the hybrids from intergeneric hybrid complex had changed a lot compared with that of intergeneric hybrid complex in the process of genetic recombination for three generations. Thus, this work analyzed the inheritance regularity for two parents inheriting to three generations, and the outcome might provide suggestions for future breeding.
2019, 20(3):728-735. DOI: 10.13430/j.cnki.jpgr.20180816001
Abstract:Ipomoea pes-caprae (L.) R. Brown is one of the perennial wild species of sweetpotato, a perennial vine plant which grows on tropical and subtropical beaches. It is one of the landscaping plants in coastal areas with strong salt tolerance. The study of Ipomoea pes-caprae genome-wide can provide reference for the improvement of salt-tolerant varieties of Sweetpotato and the innovation of salt-tolerant sweet potato germplasm resources. In order to reduce the blindness of whole-genome deep sequencing, this experiment aims to understand the genome overview and provide insight for the following mapping of the whole genome. We performed the experiments in preliminary estimation of the genome size of Ipomoea pes-caprae by flow cytometry, generation of high-throughput sequencing datasets, and the bioinformatics analysis of genomic profiles such as Ipomoea pes-caprae GC content, heterozygosity, and repeat sequences. The results showed that the genomic size by using the flow cytometry was 1012.99 Mb, and the clean data of Ipomoea pes-caprae was 21.71 Gb by genome-wide Survey. By integrated analysis with 30x genomic dataset, its genome size was re-estimated to be 1041.65 Mb. K-mer analysis suggested 74.52% of repeated sequences of the Ipomoea pes-caprae genome. The heterozygosity rate was 0.99%. The initial depth of GC and the content distribution were abnormal after initial assembly. The stratification phenomenon may be related to the high heterozygous rate of the Ipomoea pes-caprae genome. Thus, this work reported the preliminary information of the Ipomoea pes-caprae genome, which lays a foundation for further genome-wide deep sequencing and salt tolerance gene mining.
2019, 20(3):736-749. DOI: 10.13430/j.cnki.jpgr.20181204002
Abstract:SQUAMOSA promoter binding protein-like (SPL) is one of the most important transcription factors in plant. The members of this family contain a highly conserved SBP (Squamosa-promoter Binding Protein) domain, and involve in regulating plant growth, secondary metabolism, hormonal signal transduction and abiotic stress. In this study, twenty-six SPL family genes (ItbSPL) were identified using the SBP Hidden Markov Model (HMM), Blastp, CDD and SMART from Ipomoea triloba (I.triloba) genome, which is a wild diploid progenitor of the sweetpotato. The ItbSPL members were unevenly distributed on 12 of the 15 chromosomes of I.triloba. Phylogenetic analysis with the newly identified 26 ItbSPL genes and 116 SPL genes from bryophytes, dicotyledons and monocotyledons showed that the 26 ItbSPL genes were classified into 7 sub-groups based on the similarity of conserved SBP domain with the orthologs in Arabidopsis thaliana. By analyzing gene structure and motif composition, the number of exons and motif of ItbSPL were different among different evolutionary clades. SPL genes from I.triloba and Arabidopsis were grouped together, suggesting a similar function of SPL genes. PsRNA Target prediction suggested 14 of the 26 ItbSPL genes contained complementary sequencesof miR156t, and 13 ItbSPL genes of them had PCR production. Furthermore, qRT-PCR showed the 13 ItbSPL genes had lowest expression in stem, where the expression of miR156 was highly accumulated, suggesting that the 13 ItbSPL genes might be the targets of miR156. Taken together, these results will be helpful for future studies on the identification, evolutionary and function analysis of SPL genes in hexaploid sweetpotato.
2019, 20(3):750-759. DOI: 10.13430/j.cnki.jpgr.20180929001
Abstract:FTL (F-box Triple LRR ) protein belongs to the family of F-box proteins that play an important role in tolerance to low temperature. In this study, an MsFTL gene was isolated by candidate gene approach from alfalfa, and this gene was differently expressed in leaf under cold stress. The full-length cDNA of MsFTL gene was 1422 bp, which putatively encoded for 473 amino acids. By bioinformatic analysis, the MsFTL protein was found to carry an F-box domain and three LRR repeats in C-terminus. MsFTL showed homology closely to XP_003626345.1, a member of F-box/FBD/LRR-repeat protein in Medicago truncatula, with 11 differential sites between the two proteins. The expression of MsFTL was induced by low temperature, salt, drought stress and ABA treatments. We generated the transformation construct and transformed the MsFTL into tobacco. Under -4°C, wild-type tobacco leaves showed remarkable wilting, while the transgenic plants presented slightly stressed phenotype.Transgenic plants accumulated higher content of soluble protein and soluble sugar than that of wild-type. The activity of SOD and CAT in transgenic plants was higher than those of wild type under low temperature (4°C) for 24 h. Moreover, the MDA content in transgenic plants was lower than that of wild type. Thus, these results suggested that overexpressing MsFTL might significantly improve tobacco plant tolerance to low temperature stress.
2019, 20(3):760-768. DOI: 10.13430/j.cnki.jpgr.20180829002
Abstract:This study reported the isolation of CiUPF0114 gene from Caragana intermedia, which contained an 876 bp open reading frame, encoding for a protein with 291 amino acids. The predicted isoelectric point and molecular weight of CiUPF0114 were 9.83 and 32.13 kD, respectively. The expression level of CiUPF0114 gene was significantly up-regulated under drought, dehydration or cold treatments. Furthermore by genome-wide screening, a total of 29 UPF0114 gene family members were identified from eight legumes, Arabidopsis and rice. The UPF0114 genes from were divided into subfamily A and subfamily B according to phylogenetic analysis. The A subfamily was further divided into two groups, A1 and A2. CiUPF0114, a gene from Caragana intermedia, belongs to the B subfamily. These results might lay the foundation for further study on the functions of CiUPF0114.
2019, 20(3):769-780. DOI: 10.13430/j.cnki.jpgr.20181008001
Abstract:Telomerase is a ribonuclear protein complex with reverse transcriptase activity in eukaryotic cells, with significance on maintaining DNA integrity at the ends of eukaryotic linear chromosomes. The telomerase reverse transcriptase (TERT) is the key subunit of telomerase. Currently, researches on characterization of the TERT promoter is mainly focused on tumor cells, and studies of plant TERT promoter remain unclear to date. In this study, we applied bioinformatic tools to investigate the TERT promoters of Arabidopsis thaliana and other plants, performed the phylogenetic analysis with TERT promoter sequences, and analyzed the TERT gene expression through semi-quantitative RT-PCR. The results showed that the TERT promoter was highly conserved on sequence similarity in the same group of plants. The TERT gene promoter has several regulatory elements related associating to drought, salt and hormone were found. By RT-PCR analysis, the transcription level of AtTERT in Arabidopsis mutants were always lower than in wild type under normal and stress conditions. In relative to the wild type, the AtTERT mutants became more sensitive under high salt and drought conditions, but no visible difference under abscisic acid (ABA) and high temperature. Taken together, our results verified the prediction of cis-acting elements of the AtTERT gene promoter, which might be important in responses to salt and drought stresses.and The preliminary result suggestedily proved that the AtTERT promoter regulates the AtTERT gene transcription expression of AtTERT, providing an important reference for the future research on revealing the expression mechanism of this gene.
2019, 20(3):781-789. DOI: 10.13430/j.cnki.jpgr.20180918001
Abstract:Real-time fluorescence quantitative PCR is an effective method to quantify the transcriptional profile of target genes. Use of proximal gene as internal reference is essential when performing qRT-PCR experiments. The Actin (ACT) gene is highly conserved cross species and expressed stably and is often used as an internal control. In order to obtain the ACT gene of cauliflower, the ACT gene of cauliflower was cloned by RT-PCR method (GenBank ID: MG598643)1. The open reading frame (ORF) is 1,134 bp, encoding 377 amino acids with a predicted molecular weight of 41.77 kD and a hypothetical isoelectric point of 5.395. Wolf Psort analysis indicated that BobActin protein was located in the cytoplasmic matrix, and Motif Scan analysis showed that BobActin protein had the conserved actin at position of 4-377 sites. BobActin shared 90% identity with the homologous proteins from genus Brassicacea, such as Brassica oleracea var. oleracea, Brassica rapa and Brassica napus. A pair of qRT-PCR primers was designed from the BobActin gene sequence, and this combination showed high specificity and amplification efficiency. qRT-PCR analysis indicated that the BobActin gene was stably expressed in tissues of cauliflower, including root, stem, flower ball, leaf, even under various stress treatments (low temperature, high temperature, salt, drought and ABA). Thus, this gene might serve as an internal reference being suitable for gene expression in cauliflower.