| The low chilling requirement peach was main culture variety in protected cultivation, but the higher quality low chilling requirement peach variety was very little, starve for breeding new higher quality varieties in production. At present, the general crossbreed was main method in peach breed, however, the seedling of fruit tree has a stage that can not made flower by any methods before reproductive stage, this stage called juvenile stage. The juvenile stage limited the breeding course. In order to accelerate the breed and spread of new and excellent low chilling requirement peach varieties, this study was conducted with the bud seedlings and grown trees of six peach varieties Mayglo, Maravilha, EarlyRed 2, Yu hua lu, Liu yue bai and Ju hua tao; the one-year old trees of three varieties Nan fang zao hong, Qian nian hong and Shu guang and the seedlings of three crossed assembled (Sunplash×96-1-3), (Mayglo×Ju hua tao) and (Okubo×Tian jin shui mi). The characters of biology and characters of physiology and biochemistry of them were researched. The results of this study indicated that:The time of budding and unfolding of leaf was delayed in spring, the falling time of leaf was ahead in autumn, and the time of the vegetative growth stage was decreased, the increase percent of diameter of stem was decreased along with the increase of chilling requirement of varieties or seedlings in the annual growth period.In the protected cultivation condition, there was one peak in the growth process of new extensive roots, this peak appeared in the prophase of growth period, after that, the quick growth of new shoots restrain the occurring of new extensive roots, this made the occurring rate dropped quickly. The new absorbing roots also has one peak that appeared in the prophase of growth period. The relation between the occurring of new roots and the growth of new shoots were assorted with each other and affected each other. The occurring rate and quantity of new extensive and absorbing roots of low chilling requirement peach variety Nan fang zao hong was better than other two varieties. The average Pn of whole-day, the changes wave of Pn of whole-day, the sensitivity to light and temperature gradually increase along with the increase of Chilling requirement. This characters was the results that different chilling requirement peach varieties developed adaptability to the entironment of their origin place.Along with the increase of chilling requirement of varieties, the time of each phase in the processes of flower bud differentiation was delayed, the sepal stage was extended and the pistil stage was shorten,the time difference of petal and stamen differentiation stages among different varieties was little. The chilling requirement of variety and environment factors affect the solubility protein content, dissociate amino acid content, and solubility carbohydrate content in leaves. For the low chilling requirement peach variety, the start time of each differentiation stage was earlier than the long chilling requirement peach varieties, which made the low chilling requirement peach varieties in the better growth phase during the flower bud differentiation, this maybe the reason cause the content of metabolize substance of leaves was higher than the long chilling requirement peach varieties. For the long chilling requirement peach varieties, however, the start time of each differentiation stage was late,especially for the pistil differentiation stage both the provide of metabolize substance and the differentiation time were limited,which maybe affect the quality of flower bud differentiation。All the two-years old low chilling requirement peach seedlings had developed flowers, but for two-years old middle and long chilling requirement peach seedlings only have 57% and 20% had developed flowers, respectively. This indicated that low chilling requirement peach seedlings has came into reproductive stage after planted two years, however, the middle and long chilling requirement peach seedlings have a longer juvenile s...
|
PDF Full Text Request