| Cucumber is one of the main vegetable crops cultivated in my country.It likes warmth,fears severe cold,and is afraid of high temperature.Long-term high temperature stress in summer will reduce the quality and yield,and affect the growth in cucumbers.This work studies high temperature from the following three aspects on the development of cucumber female flowers: 1)The effect of high temperature on the number of female flowers and the first female flower node;2)The effect of natural high temperature in the field on the flowering time of all female cucumber varieties;3)The selection of cucumber commercial varieties which have high tolerance to high temperature,high yield and quality.The research results are as follows:1.Long-term high temperature will reduce the number of female flowers on the main stem of cucumber,and raise the first female flower node.Using cucumber inbred line CU2 and Xintaimi as the test materials,we set the normal temperature control group and the 15 d and 20 d high temperature treatment groups,Experiments in Spring and Autumn showed that the number of female flowers in each group in Spring was higher than that in Autumn,and the node number of first female flowers was lower than in Spring;the number of female flowers in each group of Xintaimi was higher than CU2,and the node number of first female flowers was lower than CU2.CU2 is more sensitive to high temperature.Under high temperature stress,the node position of the first female flower is significantly increased,and the number of female flowers is significantly reduced.After 20 days of high temperature treatment,the phenomenon of undifferentiated female flowers appears.2.In the high temperature treatment test on commercial species,it was found that the number of female flowers within 20 nodes of Daewoo Horticulture No.706 after 15 d and20d high temperature treatments were 15.44 and 12.71,respectively,which is the highest among all tested varieties.The number of female flowers was compared with the control group,the variety decrease 9.18% and 25.24%,which was the lowest among all tested varieties.The first female flower node remained at 4.33 and 4.67,which was the lowest among all tested varieties.3.High temperature will affect the time of flowering of the first female flower of cucumber gynoecious materials.According to the statistics of the flowering time of gynoecious materials of different combinations,it is found that the time of flowering may be related to the genetic background.Parents SB-2 and Gy14 was affected by high temperature as early flowering,and the flowering time was concentrated on the 35 th day,while AM297 was affected by high temperature as late flowering,and the flowering time was after the 48 th day.The flowering time of the first female flower in 1983 G was relatively scattered.From the 38 th day to the 53 rd day,23 plants successively opened the first female flower.Affected by high temperature,most of the first female flowers of Gy14×AM297 F2 population will bloom on the 37th-45 th day,but there will be late-flowering plants later;SB-2×AM297 F2 population will have obvious early flowering due to high temperature;1983G ×AM297 F2 population was affected by high temperature and showed obvious late flowering.4.In the autumn of 2019,the comparison test of cucumber yield in commodities under natural high temperature in the field showed that,single fruit weight of Daewoo Horticulture No.706 reached 259.43 g,the yield per plant was 2.07kg/plant,and the yield was 108780.00kg/hm2,which is the highest among the tested varieties;in a repeated experiment in 2020,it was found that the single fruit weight of Daewoo Horticulture No.706 reached 279.27 g,the yield per plant was 2.23kg/plant,and the yield was 117293.08kg/hm2,which was still the highest among all tested varieties. |
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