为阐明不同类型玉米自交系抗旱性的差异特征, 筛选抗旱玉米自交系。以陕A群、陕B群在多环境,少施肥和少灌溉条件下选育的33份玉米自交系和4份骨干玉米自交系(郑58,昌7-2,PH6WC和PH4CV)为材料,通过大田控水试验,调查了玉米自交系的穗位叶SPAD值、干物质积累量和茎秆强度等生理指标,采用逐步回归分析方法建立最优回归方程, 筛选抗旱性的评价指标。结果表明：穗位叶SPAD、茎秆强度和花后干物质积累量,可作为玉米自交系抗旱性的第2性状筛选指标。以籽粒产量作为第1性状指标, 可将37份玉米自交系划分为12份高产抗旱型, 13份低产不抗旱型, 7份低产抗旱型和5份高产不抗旱型。以抗旱指数和抗旱隶属度为指标,将37份玉米自交系可分成3种类型, 其中抗旱性较强的玉米自交系2份,抗旱性中等的玉米自交系15份,抗旱性较差的材料20份。综合分析, ‘2013KB-47’、‘2013KB-37’、‘KA225’、‘KB081’、 ‘L123098-2’ 和‘KA105’等6份玉米自交系具有穗位叶SPAD高、茎秆强度大、花后干物质积累量高和籽粒产量高, 抗旱指数高,抗旱能力强的特点。因此, 强化育种环境的选择压力, 实施干旱胁迫的选择策略,可有效提高玉米种质对水分的利用效率。
英文摘要:
To elucidate the differential of drought resistance and screen drought resistance lines in maize inbreds. Thirty-seven maize inbred lines including thirty-three lines bred from Shaan A and Shaan B groups under many locations, low fertilization and low irrigation as materials and four elite inbred lines (zheng58, chang7-2, PH6WC and PH4CV) as controls, were planted under different irrigation conditions, traits including SPAD-value of ear leaf, dry matter accumulation and straw stiffness were collected, used for establishing theSoptimumSregressionSmodel by stepwise regression analysis and define the selection index of drought resistance in maize inbreds. The results elucidated that straw stiffness, dry matter accumulation after flowering and SPAD reading from ear leaf could be used as a secondary drought resistance index in maize. The filed as the primary index, 37 inbred lines could be divided into 12 high-yield of drought-resistant type, 13 low-yield of drought-susceptible type, 7 low-yield with drought-resistant and 5 high-yield with drought- susceptible type. Meanwhile, the degree of membership and the drought index were used to classify the resistance degree of the 37 inbreds by clustering method, two high resistant inbred, fifteen resistant inbreds, twenty susceptible inbreds were obtained. The ‘2013KB-47’,‘2013KB-37’, ‘KA225’,‘KB081’, ‘L123098-2’ and‘KA105’as the as the maize inbred lines have the characteristicsSof high yield, the SPAD-value of ear leaf, the straw stiffness, the dry matter accumulation, the drought index, have the strongest resistance to drought. Therefore, strengthening the selection pressure of breeding environment and carrying out the strategy of drought stress selection, which can effectively improve the water utilization efficiency of maize germplasm.
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