Accumulation and Distribution Characteristics of Dry Matter of Super High Yield Wheat under Rice Stubble in Middle and Lower Reaches of the Yangtse River

Wheat grain yield mainly comes from production,accumulation and transport of photosynthetic products.In order to understand the accumulation and distribution characteristics of dry matter in super high yield wheat population in rice-wheat cropping system in the lower-middle reaches of the Yangtse River,the medium gluten wheat variety Yangmai 20 was used as the material,a field experiment in rice-wheat cropping system was carried out.The main results were as follows: A reasonable adjustment of dry matter accumulation amount(DMAA) from jointing to booting and suitable increasing DMAA from booting to anthesis were the basic factors to obtain high yield to super high yield of wheat in rice-wheat cropping system.Furthermore,on the basic formation of the population with right amount of dry matter accumulation at anthesis,improvement of DMAA after anthesis and at maturity was the key factor to realize the goal of high yield to super high yield of wheat in the lower-middle reaches of Yangtze River.For super high yield of wheat in rice-wheat cropping system,the corresponding population DMAA was 12 800～13 600 kg·hm-2 at anthesis,while after anthesis and at maturity,it was 7 200 and 20 000 kg·hm-2 or above,respectively.DMAA in leaf of the population at anthesis was parabolic correlation with DAMA after anthesis and at maturity,while DMAA in stem and spike were linear correlation with DMAA at maturity.Therefore,at anthesis,DMAA in leaf was 3 300～3 400 kg·hm-2,with 7 500 kg·hm-2 and 2 000 kg·hm-2 or above in stem and spike,respectively,were benefit for the improvement of yield.