Comprehensive Evaluation Of Drought Resistance In Field And The Expression Study Of Gene Of Drought Resistance

Wheat is one of the most important food crops in our countryeven in the world.Drought is one of the environmental factors which have seriously impact on wheat growthand development, limiting wheat production. Identification and breeding the varieties ofdrought-resistant is one of the effective ways to reduce the production losses from thedrought. Different varieties have different performance of drought resistance and theirdrought resistance mechanism also differ from each other. Regional climate characteristicsappear many and varied. The wheat varieties of drought resistance should be cultivated tosuit the local area and improve the economic benefit.1. This experiment aimed at48wheat varieties that they have different droughtresistance and come from different regions. The following indicators: the flag leaf area,spike length, length from flag leaf pulvinus to spike base(LFS), peduncle length(PLE), thetotal spikelet, effective spikelet per spike, grains per spike, flag leaf relative watercontent(RWL), water loss rate of cutting leaves(RWL), plant height, spike number per unitarea, photosynthetic rate(Pn), transpiration rate(Tr), stomata conductance(Cond),intercellular CO2concentration (Ci),1000-kernel weight, bulk density, plot yield andwater use efficiency (WUE)were investigated, respectively in rained and well-wateredenvironments. The drought resistance coefficient (DRC) of each index was employed as ameasure of drought resistance. The results showed that the19single index could beintegrated into8independent comprehensive components by using principal componentanalysis. The comprehensive indexes were calculated, and the drought comprehensiveresistance was evaluated by using membership function method in local area.2. The drought resistance indexes were chose to evaluate the resistance drought byprincipal component analysis method. As following: the panicle characteristics (spikenumber per unit area, spike length, spike grain number, the total spikelet, effective spikeletper spike), photosynthesis related index (flag leaf area, Pn, Tr, Ci), moisture related index(WUE, RWL), plant morphological characteristics (LFS), production index, the grainindex (1000-kernel weight, bulk density). 3. Laboratory test involved40wheat varieties that they have different droughtresistance and come from different regions. They were treated with20%PEG–6000for4day in Seedling stage, setting the water treatment for contrast. The relative expressionrevel of P5CS gene, BADH gene, Mn-SOD, Zn-SOD, DREB gene and DRO1wereanalyzed in40wheat varieties by RT-qPCR. Results show that BADHb gene, DEEBagene and DRO1gene are more closely relation to the wheat drought resistance under thecondition of this experiment;4. With the relative expression revel of the above three drought resistance gene as theevaluation index, combining with membership function method, there was acomprehensive evaluation of the40wheat varieties. The results are as follows:cangmai6005, xinong538, yunhan22-33, luohan9, chang6359, luohan2, qingmai6,jinmai47, luohan13, yanzhong13and linfeng3were rated as high drought-resistancevarieties; yunhan20410, han5316, jimai22, canmang119, yannong21, heng4399,yannong19, zhongmai175, shimai15, shannongyoumai2, shimai22, lumai21andhengguan35were rated as moderate drought-resistance varieties.5. With the comprehensive consideration about the test materials, the screening resultof the drought resistance varieties was consistent both in field and laboratory.