Effect Of Dehydrating Agent And Harvesting Modes On Seed Vigor Of Wheat

In order to clarify the grain dry matter accumulation patterns and seed vigor differences of wheat at different panicle and grain positions,to determine the regulatory role of dehydrating agent and harvesting modes in the production process of wheat high-vigor seeds.Two main wheat cultivars,Shannong 23 and Jimai 22,were used as experimental materials in 2018-2019,to study the effects of different harvesting time and modes on seed vigor of wheat.The effects of spraying dehydrating agents on the water moisture and seed vigor of wheat seeds at different time after anthesis were studied,which provided a basis for the production of high vigor wheat seeds.The results show:1.There are differences in the dry matter accumulation rules of grains at different panicle positions and grain positions.The dry matter accumulation of the two cultivars with different panicle position and grain position showed an increasing trend with the grain filling process first and then slow,and the dry matter accumulation of the grain in the middle of the panicle was significantly higher than that of the upper part;the dry matter accumulation of inferior grains was significantly higher than that of upper grains.The dry matter accumulation of grains at different panicle and grain positions of Shannong 23 started to increase slowly after 30 days after anthesis and remained relatively stable at 35 days after anthesis;the dry matter accumulation of grains at different panicle positions and grain positions of Jimai 22 remained relatively stable at 30 days after anthesis.2.There are differences in seed vigor of wheat cultivars at different panicle positions and grain positions.The seed vigor of the whole panicle and middle panicle of Shannong 23 was not significantly different from that of the upper and lower panicles,but the seed vigor of the lower panicle was significantly higher than that of the upper panicle;There was no significant difference in seed vigor among whole panicles,middle panicles and lower panicles of Jimai 22,and they were significantly higher than those in upper panicles.In terms of grain position,there was no significant difference in seed vigor between the different grain positions of Shannong 23,and the seed vigor of the lower grains of Jimai 22 was significantly higher than that of the upper grains.3.The harvesting time has a certain effect on the vitality of wheat seeds.The seed vigor of Shannong 23 had no significant changes in the three harvesting periods.The seed vigor of Jimai 22 after 35 days of anthesis was significantly higher than that of mature seeds.The 100-seed weight of the two cultivars at 30 days after anthesis was significantly lower than that at the mature stage,and the 100-seed weight of the seeds at 35 days after anthesis was not significantly different from the mature stage.Therefore,Shannong 23 harvested better at 35 days or mature,and Jimai 22 harvested better at 35 days after anthesis.4.The harvesting modes has a certain effect on the vitality of wheat seeds.The seed vigor of Shannong 23 and Jimai 22 were harvested at 35 days after anthesis,which were significantly higher than those harvested at maturity,5.21 % and 5.80 % higher,respectively.There was no significant difference between other treatments and harvest at maturity.Therefore,it is better for both cultivars to take panicles 35 days after anthesis,taking the plants did not improve seed vigor.5.Spraying dehydrating agents in the field is best when spraying 150 mg / L glyphosate or 0.5 % sodium ethylxanthate 35 days after anthesis.It can significantly reduce the moisture content of seeds,and has no effect on seed weight and seed vigor.