玉米杂交种苗期耐低氮指标的筛选与综合评价

Indexes screening and comprehensive evaluation of low nitrogen tolerance of hybrid maize cultivars at seedling stage

  • 摘要: 为探明耐低氮玉米杂交种的苗期筛选鉴定方法, 筛选出耐低氮能力强、可推广应用到生产上的玉米杂交种, 本研究采用蛭石和珍珠岩盆栽、Hoagland营养液培养方式, 以西南地区生产中应用的51个玉米杂交种为材料, 对供试品种进行了2年的低氮胁迫苗期筛选试验。结果表明: 低氮胁迫对各玉米品种苗期主要形态、生理指标均有显著影响, 但影响的程度在指标间和品种间均有较大差异。根据相对值变异系数大小, 筛选出叶面积、氮积累量、根冠比、地上部干重、根体积、根干重和单株干重7个指标作为耐低氮能力的评价指标。以7个指标归一化的变异系数为权重进行耐低氮能力模糊隶属函数综合评价, 并与用全部指标(第1年为13个指标, 第2年为25个指标)模糊隶属函数评价和主成分分析法评价的结果进行比较, 7个指标评价结果与全部指标综合评价结果基本一致, 得出的耐低氮能力强和弱的前10个品种的重合率分别达90%和80%, 说明筛选指标的代表性和评价方法的可行性。本研究表明上述7个指标可以作为玉米苗期耐低氮能力评价指标, 并筛选出'正红311'、'成单30'、'黔北2号'等适宜于中国西南丘陵山区种植的耐低氮品种。

     

    Abstract: To develop a better screening and identification method of low nitrogen resistant hybrid maize cultivars at the seedling stage, and obtain low nitrogen tolerant maize cultivars applicable in production, 51 commercial hybrid maize cultivars were two-year treated under low nitrogen stress by the vermiculite and pearlite pot culture with Hoagland nutrient solution. The results showed that low nitrogen stress had a significant impact on the main morphological and physiological indexes of different maize cultivars at the seedling stage and the degrees of effect among the indexes and cultivars were significantly different. Based on the coefficients of variation of relative values of different indexes, total of 7 indexes including leaf area, nitrogen accumulation, root-shoot ratio, dry shoot weight, root volume, dry root weight and dry biomass weight were selected as indexes for screening and evaluation of the degree of low nitrogen tolerance of hybrid maize. The low nitrogen tolerability of hybrid maize was evaluated by using the method of the fuzzy membership function with the normalized coefficients of variation as weight of the selected 7 indexes. The evaluation result was compared with the results of the fuzzy membership function and principal component analysis using 13 indexes for the first year and 25 indexes for the second year. The comparison showed that the evaluation results of 7 screening indexes and all the indexes were largely identical. The coincidences rates of low nitrogen tolerance and sensitivity of the first 10 cultivars were 90% and 80%, proving the representativeness of the screening indexes and the feasibility of the evaluation method. The study showed that the above 7 indexes may be used to evaluate low nitrogen resistance of maize at seedling stage and to screen hybrid maize cultivars with low nitrogen resistance. In the study, 'Zhenghong 311', 'Chengdan 30', and 'Qianbei 2' were identified as low nitrogen resistant cultivars and to be suitable for the southwestern hill and mountain areas of china.

     

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