陕A群、陕B群选育的玉米自交系抗旱性鉴定

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份骨干玉米自交系为材料,通过大田控水试验,调查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。以子粒产量作为第1性状指标,可将37份玉米自交系划分4种类型,高产抗旱型12份,低产不抗旱型13份,低产抗旱型7份和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共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子粒产量高、抗旱指数高和抗旱能力强的特点。

Drought Resistance Identification of Maize Inbred Lines Selected From Shaan A Group and Shaan B Group

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 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 the optimum regression model 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 field as the primary index, thirty-seven inbred lines could be divided into 12 high-yield of drought-resistant type, thirteen low-yield of drought-susceptible type, seven low-yield with drought-resistant and five 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 maize inbred lines 2013KB-47'', 2013KB-37, KA225, KB081, L123098-2 and KA105 had the characteristics of high yield. The SPAD-value of ear leaf, the straw stiffness, the dry matter accumulation and the drought index were high, and had the strongest resistance to drought.