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Flowing Rock
Effects of Chilling and Heat Requirement Differences Between Peach Floral Bud and Leaf Bud on Their Phenological Process
In order to clarify the phenological process of flowering and leaf expanding in peach, and the effects of chilling and heat requirement differences between floral and leaf buds on the phenological process, we first evaluated the chilling and heat requirements of floral and leaf buds of 257 peach germplasms, and investigated the full bloom date and leaf expanding date, then according to the chilling requirement of floral buds, the materials were classified into 4 types of very low, low, medium and high chilling requirement, respectively, and finally the phenological process of different types of peach in different years, as well as chilling and heat requirement differences of each phenological process, were systematically discussed. The results showed that peach with very low chilling and low chilling requirements had 3 kinds of phenological process, including “flowering before leaf expanding”, “simultaneous flowering and leaf expanding” and “leaf expanding before flowering”. The phenological process of the same germplasm varied in different years, and the patterns of chilling and heat requirement differences were complex and varied accordingly. Peach with medium chilling and high chilling requirements had only 1 kind of phenological process, which was “flowering before leaf expanding”, and the patterns of chilling and heat requirement differences were simple and unvaried. The phenological process of peach floral and leaf were related to patterns of chilling and heat requirement differences, and mainly depended on the difference of heat requirement. Regardless of the chilling requirement of the floral bud, when the heat requirement of floral bud was less than that of leaf bud, the phenological process was “flowering before leaf expanding”; when the heat requirement of floral and leaf buds was equal, the phenological process was “simultaneous flowering and leaf expanding”; when the heat requirement of floral bud was greater than that of leaf bud, the phenological process was “leaf expanding before flowering”. The results indicated that the heat requirement difference of the floral bud and leaf bud was chiefly responsible for the different and variable phenological process of peach.
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Flowing Rock
Collection and Identification of Rare Germplasm Resources of the Genus Fagopyrum Mill. in Six Provinces of China
Southwestern China is internationally recognized as the origin of Fagopyrum Mill.,and its complex geographical environment and diverse climate types breed abundant wild buckwheat resources. Due to the similar ecological environment and climate,there are also a large number of wild buckwheat in some northwestern regions,contributing to a famous ethnic plant resource group with regional characteristics,which is an important basis for modern buckwheat breeding in China. In order to find out the distribution status of wild buckwheat in China and rescue the collection of wild buckwheat germplasm resources,the national survey and collection of wild buckwheat resources has been carried out since 2016 and 1014 wild buckwheat germplasm resources were collected in 6 provinces(autonomous regions) containing 42 counties(cities,districts) of western China. The phenotypic identification was performed and the classification of Fagopyrum in China was revised. The results showed that our collection included 21 species of Fagopyrum Mill.,containing a new species Fagopyrum longistylum. There are abundant genetic diversity among different wild buckwheat species,and many rare wild buckwheat species have unique character variation or excellent quality. These rare germplasm resources contain valuable gene pool,which provides valuable material basis for the yield and quality improvement of buckwheat. This study is of great significance not only to promote the classification and evolution of buckwheat,but also in crop genetic breeding,high-quality gene exploration and plant resource protection..
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