Effect Of Different Cultivating Models On The Assimilate Translocation In Dryland Wheats

The accumulation and the transfer of the water soluble carbohydrate are crucial for the yield of wheat. The filling grain period is the crucial time for yield formation, while in The Loess Plateau, during wheat grain filling process is often subjected to different levels of soil drought and atmospheric drought have seriously affected wheat grain filling process, thereby limiting the increase in production. In filling in wheat there are two main sources of soluble carbohydrates,one is using the flag leaf fixed photosynthetic products during grain filling stage,the other is to mobilize WSC which stored in the flowering stem at the day before anthesis.With the development of filling process and the flag leaf subjected to unfavorable environment conditions, accelerating the senescence of photosynthetic apparatus of wheat, so mobile the WSC storaged in the stem of the to grain is higher importance significance. So depth study of the assimilation process related key enzymes transport the relationship between yield and source-sink relations of wheat yield regulation has important scientific significance and prospects. Taking two drought-resistance wheat cultivars changwu-134 and changhan-58 (Triticum aestivum L.) as test materials, a field experiment was conducted in Changwu Agro-ecological Experiment Station on the Loess during 2008 to 2009 study the effects of different cultivating models on carbohydrate mobile. Determinate the effect of different cultivation models on SPAD values in flag leaves of wheat, sugar metabolism and yield components, the main results are as follows:1. With the succession of wheat varieties, changhan-58 varieties have the longer time stay green than that of changwu-134 in flag leaves and had a higher SPAD. In changhan-58 varieties, T3 have the highest value of SPAD in flag leaf than cultivation T2 and T4, that through the use of manures can increase wheat flag leaves stay green, which can offer a longer photosynthetic time.2. Compared with the different grain filling characteristics, which illustrate that the kernel weight of winter wheat was positive correlated with Dd (the days of whole grain filling), with Va (the average rate of whole grain filling), with D1 (the days of grain filling of gradual growth), with D2 (the days of grain filling fast growth period), with Rmax (the maximum rate of the whole grain filling) at 0.01 significant level.3. Compared with flag leaf soluble sugar and sucrose content showed that, With the succession of wheat varieties, changhan-58 varieties stored more soluble sugar and sucrose than that of changwu-134 varieties in flag leaf. In changhan-58 varieties, T3 have the most quantity of the soluble sugar and sucrose. This result showed that using the can increase the content of the WSC and sugar.4.Compared with soluble carbohydrate content in penultimate internode,with the evolution of wheat cultivars changhan-58 showed the more yield, the more contents of fructan in the penultimate internode,the more expression of FEH than that of in changwu134.In the wheat cultivars changhan58, T3 showed the highest level in yield, in contents of fructan of penultimate internode, in WUE, in activity of FEH and the expression of the gene of FEH among all the cultivating models. The transportation and mobilization WSC of pre-anthesis in penultimate internode is very important for wheat yield. So in the daily practice, should pay attention to the use of manures and fertilizer, enhancing the amount of the WSC and the transportation efficiency of WSC, which can make higher yield.5.By measured the accumulation of grain starch and its accumulation rate and the change showed that through the use of manures, it could upregulates the activity of key enzymes of starch synthesis to accelerate the accumulation of starch grain filling stage, which could help make up for the late filling of photosynthetic products in short supply.6.The results of weighting the yield of different cultivating models showed that with the succession of, the average yield of changhan-58 was 6254kg/ha, 15.3 percent much than that of changwu-134. In the changhan-58 varieties, T3 had the highest grain yield among the test materials, 10.7 percent and15.1 percent much than T2 and T4, respectively. We can infer the reason why the T3 have the highest grain yield. Compared the WUE and HI among different wheat varieties, the result showed that with the succession of wheat varieties, changhan-58 had the higher WUE and HI. In the changhan-58 varieties, T3 showed the higher WUE[18.36kg/(hm2?mm)] and HI(0.506), 7.26% and 21.6% much than changwu-134 varieties. Between the T2 and T4, althought there is no significant difference in yield, in terms of WUE and HI, T2 had higher WUE and HI. It could colcusion that only rely on nitrogen fertilizer alone can not improve plant WUE and HI, while the T3 by manure and chemical fertilizers interaction as well as split application, can increase WUE and HI.