Effects of Sowing Date and Rate on the Basal Internode Microstructure and Lodging Resistance Index in Ultra-Late Sown Wheat
In order to screen the suitable combinations of high-yield lodging resistance index in ultra-late sown wheat in northern Xinjiang,the microstructural characteristics of the basal internodes of wheat and its correlation with lodging resistance index were investigated.A split plot experiment was used,the main plot was set with three ultra-late sowing dates:S1(October 25th),S2(November 4th),and S3(November 14th),and the sub plot was set with four sowing rates:P1(337.5 kg·hm-2),P2(450 kg·hm-2),P3(562.5 kg·hm-2),and P4(675 kg·hm-2),using the local suitable sowing date and rate(September 25th,270 kg·hm-2)as the control(CK).The effects of sowing date and rate on the microstructure,lodging resistance index and yield of basal internodes during the flowering,milky and wax ripening stages of ultra-late sown wheat were studied.The results showed that,after wheat flowering,the lodging resistance index of wheat gradually decreased with growth,and the microstructure quality of basal internodes from bottom to top deteriorated,with consistent change in the 1st,2nd,and 3rd internodes.Compared with CK,the microstructure indicators(the number of mechanical tissue layers and thin-walled tissue layers,the thickness of mechanical tissue and thin-walled tissue,the number of large vascular bundles and the number of large vascular bundles,the circumference and area of large vascular bundles)of ultra-late sown wheat stem had decreased,and the microscopic structure had become smaller,and the lodging resistance ability decreased.The microstructure and lodging resistance index of wheat basal stem at the same sowing rate and different sowing dates were all S3＞S1＞S2.Under the same sowing date,as the sowing amount increased,the microstructure indicators and lodging resistance index decrease.There was no interaction effect between sowing date and sowing rate on various indicators.The lodging resistance index was significantly negatively correlated with the number of small vascular bundles in the basal internodes,and significantly positively correlated with other microstructural indicators,with thin-walled tissue had the highest effect on improving wheat lodging resistance.Increasing the sowing rate of wheat under ultra-late sown conditions was beneficial for increasing the number of spikes,compensating for the loss of grain number and thousand grain weight per spike,thereby improving yield.S2P2 had the highest number of spikes and the highest yield.Thus,sowing 450 kg·hm-2 of ultra-late sown wheat in northern Xinjiang on November 4th could achieve high yield,while also considering lodging resistance.The results of this study provide a certain theoretical basis for stable and high yield of ultra-late sown wheat.
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维普
