'Weixuan 1' Apricot Germplasm Cold Resistance Of Floral Organs And Biological Characteristics

To generalize elite germplasm and provide theoretical basis for Apricot Frost Protection measures, choose 'Weixuan 1', 'Youyi' and 'Longwangmao' as material, the experiment studied biological characteristic of the three species, including budding, flowering, floral organs cold hardiness of young fruit and fruit quality,the main results are as follows:1. The field survey results of cold resistance show that elite germplasm 'Weixuan 1'has strong ability of anti-frost. The freezing rate of 'Weixuan 1'was only 66% in -7℃, still had 1419Kg /acre yield, compared with 'Youyi', it was reduced by 23.50%, per unit area production increased by 528 Kg. And the female parent 'Longwangmao's freezing rate has been 100%.2. Select three apricot cultivars as test materials, using The Artificial Climate Chamber which can accurately simulate the natural cooling process of night cream, the study determined the supercooling point of floral organ and young fruit in the different developmental stages, counting the freezing case of floral organ. The results showed that: With the development process of the flower, from bud stage to the young fruit, the supercooling point of the three apricot varieties showed clear upward trend, indicating that reduced cold tolerance. Young fruit is the most sensitive to frost, while the flowering is the most sensitive period; the supercooling points are different in different floral organs and species, in the floral organs, supercooling point of petals is the lowest, followed by stamen, pistil was highest; among the species, supercooling point of the flower organs showed lower, the stronger the resistance. based on petal, stamen, pistil's supercooling point, the order of cold resistance was 'Weixuan 1'> 'Youyi' > Longwangmao.3. The test studied the influence of low temperature in different developmental stages in flower organ lipid peroxidation , protective enzyme activities, soluble protein and proline content, the results showed that: as the temperature dropped, generation rate, electrolyte leakage, lipid peroxidation MDA levels showed a rising trend, protective enzyme of 'Weixuan 1'showed the highest activity, Longwangmao was the worst. The temperature that protective enzyme activities decreased is slightly different of the flower organs in different speices, 'Weixuan 1' is lower than the other two species about 1℃. Soluble protein, proline content related with cold resistance of flower organs, but the soluble protein, proline content in floral organs didn't perform the law that the cold resistance is stronger, the higher the content. The integrated results suggest that in low temperature, 'Weixuan 1' had the most stress protective enzymes in floral organs , injured cells the minimum and the balance system of cells produce and eliminate free radicals is more difficult to be destroyed. Over time, floral organ sensitivity to low temperature is rising, so that the level of cells in the injured organ gradually increased. Combined with the electrolyte leakage rate and Logistic equation, fitted regression equation and calculate the temperature of the organization collapse in theory, that the semi-lethal temperature (LT50). The results of LT50 consistent with the supercooling point, and further determined the order of the cold resistance of different varieties 'Weixuan 1'> Youyi> Longwangmao.4.Phenology survey results of the three kinds of test materials show that: the florescence of 'Weixuan 1' is later than the Longwangmao and Youyi 3-5d , but not been able to avoid the high incidence of late frost, just reduced the opportunity affected by late frost, late flowering is the main reason for little or without frost damage; days of vegetative growth of 'Weixuan 1'is longer than the other two species, making it can accumulate nutrients more fully and provide a good conditions for development for the following year.5.Compared of the output and fruit quality of the three apricot varieties, the results show that: the grain yield per plant (the year were not freezing) of 'Weixuan 1' was the highest, but the nutrient content of the fruit were not significantly superior, nutrition element content of three varieties had no significant difference.