| Chinese chestnut occupies an important position as economic tree species among our country because of its rich nutritional value and its high economic value, known as the "king of fruits" reputation. Total cultivated area is rising year after year and output is the first in the world, however, the phenomenon of low yield still restricts the development of industry of Chinese chestnut. Embryo abortion directly affects the yield. This experiment, taking Chestnut "Zunyu" of Hebei province as test materials, controlling the pollination experiment, compared involucre development,ovary development, the dynamic changes of nutrient content and endogenous hormone content between normal development chestnut and abortive development chestnut, to explore the effect factors of chestnut embryonic development, to provide a theoretical basis for improving yield of Chinese chestnut, and at different stages of chestnut spraying different growth regulators, to explore the promotion of regulation of chestnut embryonic development. The results are below:1. The involucre law of normal development growth of Chinese chestnut shows the tendency of uniform growth, the daily growth of involucre vertical, involucre horizontal, involucre height are 0.063cm,0.053cm,0.049cm, its ovary morphology development presents speed up gradually and then decrease, from the day of pollination to 16 days after pollination, the daily growth of ovary vertical, ovary horizontal, ovary height are 0.013cm, 0.011cm and 0.010cm, from 16 days after pollination to a week before maturity, the daily growth of ovary vertical, ovary horizontal, ovary height are 0.035cm,0.018cm and 0.029cm, since then, the daily growth of ovary vertical, ovary horizontal, ovary height are 0.025cm, 0.002cm and 0.0002cm. And abortive chestnut from the day of pollination to 28 days after pollination speed up growth, the daily growth of involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height are 0.078cm, 0.073cm,0.057cm,0.018cm,0.011cm,0.013cm, from 28days after pollination to 63 days after pollination, chestnut grow slowly, the daily growth of involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height are 0.028cm, 0.024cm,0.033cm,0.011cm,0.006cm,0.012cm, mostly 30 days before maturity, the volume of involucre and ovary do not change, the daily growth of involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height are 0.0069cm,0.0035cm,0.0031cm,0.002cm,0.001cm,0.002cm, stented growth.2. From the day of pollination to 16 days after pollination, there is no significant difference between the normal development chestnut and abortive development chestnut of involucre and ovary, and the same as the ovule size. At 16 days after pollination, involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height of the normal development chestnut are 2.46cm,2.12cm,1.82cm,0.43cm,0.33cm,0.39cm, involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height of the abortive development chestnut are 2.23cm,1.91cm,1.53cm,0.38cm, 0.29cm,0.33cm, the normal development chestnut and abortive development chestnut becomes significant difference on ideology, at this point, the ovule vertical and the ovule horizontal are 0.75mm and0.42mm of the normal development ovule, and ovule vertical and the ovule horizontal are 0.71mm and0.27mm of the abortive development ovule, there is a significant difference of ovule size. At 31 days after pollination, involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height of the normal development chestnut are 3.89cm,3.46cm,3.14cm,0.85cm,0.58cm,0.63cm, involucre vertical, involucre horizontal, involucre height, ovary vertical, ovary horizontal, ovary height of the abortive development chestnut are 3.35cm,3.01cm,2.50cm,0.75cm, 0.50cm,0.60cm, the normal development chestnut and abortive development chestnut becomes extremely significant difference on ideology, at this point, the ovule vertical and the ovule horizontal are 1.87mm and0.85mm of the normal development ovule, and ovule vertical and the ovule horizontal are 1.21mm and 0.44mm of the abortive development ovule, there is a extremely significant difference of ovule size. Involucre and ovary development pattern is consistent with the ovule size growth rule. The abortive ovule results in the stagnation of involucres and ovary growth, abortive chestnut volume significiantly less than the normal development chestnut. The normal growth appearance of Chinese chestnut can be as an indicator of the normal embryonic development.3. Nutrition is the material base of chestnut in embryonic development. From the day of pollination to 21 days after pollination, the nitrogen content and phosphorus are beneficial to cell division which the cell number is increasing. The nitrogen content and phosphorus content of normal development chestnut are significantly higher than those of abortive development chestnut. At the 16 days after pollinaton, the potassium content of normal development chestnut is significantly higher than that of abortive development chestnut, and rising in the process of embryonic development. High level of potassium content is advantageous to embryonic development. At 31 days after pollination, nutrition and energy are needed to embryonic development, and soluble sugar and starch is an accumulation process, if the embryo is blocked, it is unable to form the accumulation of soluble sugar and starch.4. ABA content decreased and endogenous hormone content rise is beneficial to the accumulation of nutrients, and interaction of hormone of chestnut embryonic play a coordinating role. In the period of cell division, low level of ABA and high level of (GA3+IAA+CTKS)/ABA promote the accumulation of nitrogen, and ZR and IP promote the the accumulation of phosphorus. By regulating the content of nitrogen and phosphorus, endogenous hormone promote the development of involucres and ovary. In the period of cell swelling, compensatory promoting endogenous hormones and coordinate interaction between hormones, promote the accumulation of carbohydrates, are advantageous to the nutrition and energy supply in embtyonic development of Chinese chestnut.5. At the beginning of full bloom spraying SA could significantly improve the fruiting rate, the number of nuts in each bud and soluble sugars content, starch content and protein content of chestnut, and spraying SA before the period of immature embryo development could increase the fruiting rate, which have a certain impact on the yield and could not improve the nut quality to increase nutrient content. Therefore, it is recommended to spray 0.2nmol/L SA at the beginning of full bloom, compared to the treatment CK, the fruiting rate from 84.59% to 97.70%, increased by 15.5%, the number of nuts in each bud increased from 1.67 to 3, increased by 79.64%, the soluble sugars content increased from 17.56% to 20.93%, increased by 19.19%, the starch content increased from 42.51% to 47.27%, increased by 11.20%, the protein content increased from 7.23% to 7.67%, increased by 6.09%. According to different target fill spray before the period of immature embryo development, if increase production, suggest spraying O.OOlmg/L BR, compared to the treatment CK, the fruiting rate increased from 83.74% to 100%, increased by 19.42%, the number of nuts in each bud increased from 1.33 to 3, increased by 125.56%, if improve quality, suggest spraying O.Olmg/L BR, compared to the treatment CK, the soluble sugars content increased from 16.91% to 21.37%, increased by 26.37%, the protein content increased from 7.56% to 7.99%, increased by 5.69%. |
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