Effects Of Dust On Walnut Flower Organ And Fruit Growth After Pollination In The Southern Xinjiang Basin

Southern Xinjiang basin is the most serious area of sand and dust storm mainly in the spring and summer. When walnut flowering period suffered dust weather, whether it had a negative impact on walnut flowering organs and fruit formation after pollination. Based on dust have a negative impact on walnut flowering organs and fruit formation after pollination, walnut cultivars in Wushi County were observed in this research. The results verified that dust have a negative impact on walnut flowering organs and fruit formation after pollination and revealed the adverse effect physiological mechanisms by analyzing the male and female phenology, flower organ and fruit formation after pollination under dust comparatively. The main results were as follows:When walnut flowering period suffered dust weather, the dust would extend elongate flowering phase duration, shortened full flowering phase duration, the late flowering phase duration of male flowers and full flowering phase duration, late stage of flowering phase duration and the late flowering phase duration of female flowers, which shorten two days of male flower phenology and three days of female flower, and speed flowers dry, aging and even death.The dust had a significant inhibitory effect on average two-day growth, the amount of a single bud shedding, and pollen viability of Xinjiang walnut male flowers. It would cause the male inflorescence two-day growth decreased 2.01 mm maximally, the average total growth 19.34 mm, the amount of a single bud shedding 2.08×104and percentage of pollen grain viability 16.44%, clogged the hole of pollen germination, reduced pollen germination rate on stigma and extend pollen tube arrival time, it also lead to increase SOD, POD activity and MDA, Pro content of each male flowering stage in different degrees.The dust had a significant inhibitory effect on stigma length and receptivity of Xinjiang walnut male flowers. It would cause the final average length of walnut stigma reduced 0.68 mm, and decreased stigma mucus making stigma atrophy to smaller size, the amount of pollen on the stigma attached, weaken the stigma receptivity, and accelerated female flowers dry, even death. it also lead to increase SOD, POD activity and MDA, Pro content of each female flowering stage in different degrees.The dust would have adverse impact on fruit formation; it would decrease the rate of the walnut length and diameter in rapid growth, but have no significant effect on fruit size ultimately.