小黑麦在南疆抗旱性综合评价

The Comprehensive Evaluation of the Triticale Drought Resistance in South Xinjiang

摘要: [目的]新疆属于我国极度干旱缺水的省份，南疆更是以沙漠和戈壁为主，水是限制南疆农业发展的第一因素。筛选出适合于旱地栽培的品种，对于南疆生态恢复和经济发展非常重要。小黑麦(Triticale)属于较抗旱的作物，但不同品种间抗旱性存在着较大差异。本试验旨在探讨南疆小黑麦不同品种(系)的抗旱性能，分析小黑麦抗旱性遗传特征，筛选抗旱性鉴定指标并建立可靠的农艺产量性状评价数学模型，为南疆地区选育抗旱小黑麦新品种以及生产推广奠定基础。[方法]以20个小黑麦品种(系)为试验材料，采用田间鉴定法，在野外自然气候状态下，随机区组设计，干旱处理和有压滴管灌水处理两种方式，可真实反映出小黑麦在大田干旱状态下的实际胁迫环境及真实生长状况。将田间记录和室内考种方式相结合，对2种处理下各材料的株高、生育期、旗叶长、旗叶宽、穗下节长、有效穗数、穗长、主穗粒数、千粒重、容重、籽粒亩产、鲜草产量等共计12个农艺性状进行测定，以各单项性状的抗旱系数作为评价抗旱性的依据，运用主成分分析、聚类分析和逐步回归等方法对其抗旱性进行综合评价及分类，并分析小黑麦品种(系)各抗旱型的产量性状表现特点。[结果]在干旱胁迫下，参试的12个性状与正常灌水对照相比，均有所下降，但所有品种各单项性状的变异幅度均有差异。通过主成分分析，本试验将干旱胁迫处理下小黑麦的12个单项性状浓缩成了5个相互独立的综合性状。通过隶属函数分析，得到不同的小黑麦品种抗旱性综合评价D值，并通过聚类分析，将20个小黑麦品种划分为3种抗旱类型，其中中度抗旱型品种4个，中间型10个，干旱较敏感型6个。进一步运用逐步回归分析法建立了可靠的小黑麦抗旱性评价数学模型D = −0.483 + 0.297X6 + 0.205X7 + 0.387X9 + 0.333X11 + 0.411X12，该方程的决定系数是0.9815，同时筛选出了对小黑麦抗旱性有极显著影响的5个单项性状，分别是有效穗数，穗长，千粒重，籽粒亩产和鲜草产量。对该数学模型的拟合精度进行评价，各品种(系)的拟合精度均在92%以上，说明本试验筛选出来的鉴定性状对小黑麦抗旱性具有显著作用，该模型能用于小黑麦抗旱性综合评价。在此基础上，将综合聚类与逐步回归分析相结果，分析了各个抗旱类型材料的产量性状特点。结果发现相比干旱较敏感类型品种(系)，中度抗旱类型的品种能够在有效穗数、穗长、千粒重、籽粒亩产和鲜草产量等性状上保持较高水平。[结论]中度抗旱类型的小黑麦品种(系)能够在有效穗数，穗长，千粒重，籽粒亩产，鲜草产量等这5个产量性状上比干旱较敏感类型品种(系)保持更高的水平，在相同的干旱环境下，可通过测定其它品种的有效穗数，穗长，千粒重，籽粒亩产，鲜草产量这5个产量性状来判定目标品种抗旱性的强弱，可为抗旱栽培、育种及种质资源的鉴定与筛选提供理论依据。

Abstract: [Objective] Xinjiang is the most extremely water scarcity area in China, Southern Xinjiang is dominated by desert and Gobi, and water is the most limited factor constraining the agriculture development. It is important to screen the suitable varieties for dry farming to the ecological restoration and economic development of Southern Xinjiang. The Triticale is a kind of drought resistant crop, however the drought resistance of different varieties differed wildly. The purpose of this experiment is to explore the drought resistance of different Triticale varieties (lines) in South Xinjiang, analyze the genetic characteristics of the drought resistance of forage type triticale, screen the identification indexes of drought resistance and establish a reliable mathematical model for the evaluation of agronomic yield characters, so as to lay a firm foundation for breeding new varieties of drought resistant forage type triticale and production extension in South Xinjiang. [Methods] Twenty Triticale varieties (lines) as experimental materials, field identification method was used, the field drought as drought treatment and pressure drip irrigation treatment as the irrigation with random block design. Combining the field record with the laboratory test, 12 agronomic characters including plant height, growth period, flag leaf length, flag leaf width, node length under the ear, ef-fective ear number, ear length, grain number of main ear, 1000 grain weight, grain bulk density, grain yield/666.6m2 and fresh grass yield were measured under the two treatments. The drought resistance coefficient of each character was used as the basis for the evaluation the drought re-sistance, the principal component analysis, the cluster analysis and stepwise regression were used to comprehensively evaluate and classify the drought resistance, and to analyze the yield characters of drought resistance Triticale varieties (lines). [Results] Under the drought stress, compared with the irrigation control, the tested 12 characters of decreased, whereas the variation of each character with all varieties was different. Through principal component analysis, the 12 characters under drought stress were condensed into 5 independent comprehensive characters. Through membership function analysis, the comprehensive evaluation D value of drought resistance of different forage type triticale varieties was obtained. Through cluster analysis, 20 triticale varieties were divided into three types of drought resistance, including 4 moderate drought resistance type varieties, 10 intermediate type varieties and 6 drought sensitive types. Furthermore, by stepwise regression analysis, a reliable mathematical model for evaluating the drought resistance of forage type triticale was established: D = −0.483 + 0.297X6 + 0.205X7 + 0.387X9 + 0.333X11 + 0.411X12, with the decisive coefficient of 0.9815. Five single characters that had a significant effect on the drought resistance of forage type triticale were screened, which were the effective ear number, ear length, 1000 grain weight, grain yield per unit area and fresh forage yield. The fitting accuracy of the mathematical model was evaluated, and the fitting accuracy of each variety (line) was more than 92%, which indicated that the identification characters screened in this experiment had significant effect on the drought resistance. The model can be used for the comprehensive evaluation of the drought resistance of forage type Triticale. On this basis, the comprehensive clustering and stepwise regression analysis were used to analyze the yield characteristics of various drought resistant materials. The results showed that compared with the drought sensitive varieties (lines), the middle drought resistant varieties were able to maintain a higher level in effective ear number, ear length, 1000 grain weight, grain yield per unit area and fresh forage yield. [Conclusion] Compared with sensitive drought resistance forage type triticale varieties (lines), the moderate drought resistance can maintain a higher effective ear number, ear length, 1000 grain weight, grain yield per unit area and fresh forage yield. Under the same drought environment, the five characteristics of effective ear number, ear length, 1000 grain weight, grain yield per unit area, fresh forage yield can be measured to determine the drought resistance of the target varieties, which can provide theoretical basis for drought resistance cultivation, breeding and germplasm resources identification and selection.