不同耐低磷玉米自交系生长发育特征研究

采用盆栽和田间试验方法研究了低磷胁迫对不同耐低磷玉米基因型全生育期生长发育的影响。结果表明,不同自交系在生长发育过程中对低磷胁迫的反应存在明显差异,在苗期耐低磷自交系植株干重和缺磷症状的相对值显著高于敏感自交系;到拔节始期,耐低磷自交系仍无缺磷症状,而敏感自交系症状加剧;进入生殖生长期后,耐低磷自交系孕穗期上部叶干重、茎干重受低磷影响的程度显著低于敏感自交系;至吐丝期,不同自交系间的耐低磷差异除了表现在植株干重上外,穗位高、雄花分枝数、功能叶面积也出现显著差异,低磷胁迫下耐低磷自交系这几个性状的相对值均显著高于敏感自交系;在成熟期,低磷胁迫下耐低磷自交系的相对产量较大,敏感自交系的相对产量较小。受低磷影响,敏感自交系的抽雄期、抽穗期、吐丝期和散粉期都显著延迟,而耐低磷自交系受影响较小或几乎不受影响。

Characteristic of growth and development of maize inbreds with different phosphorus efficiency under low-P stress

The effects of low-P stress on growth and development of 5 maize inbred lines with different phosphorus efficiency were evaluated at seedling,jointing,earing,silking stages under pot culture respectively.Seed yields was also investigated under the field condition.The results showed that there were remarkable different responses to low-P stress at different growing time among various maize genotypes.At seedling stage,the relative magnitude of plant dry matter weight and P-deficiency symptom of P-tolerance genotypes were markedly higher than those in P-sensitive genotype.As to jointing period,the P-deficiency symptom of P-sensitive genotype was aggravated,while there was still no P-deficiency symptom of P-tolerance genotypes.After entering reproductive growth phase,the dry matter weight of upper leaves and stem of the P-tolerant genotypes,compared to P-sensitive genotypes,was more significantly influenced by low-P stress.At the silking stage the response discrepancies of low-P stress of different inbreds take shape not only on plant dry matter weight,but also on plant height,diameter of stem,dry weight of stem,area and dry weight of functional leaves,and number of staminate flower branches.The relative magnitude of captioned parameters of P-tolerance genotypes was significantly higher that those of P-sensitive one.However,there were different biologic characteristics in different P-tolerant genotypes.Eventually,low-P stress decreased the economic yields of the inbred lines,but the P-resistant genotypes had higher relative seed yield compared to P-sensitive genotypes.Low-P stress prolonged the growing time and delayed tasselling,earing,pollen-shedding,silking of P-sensitive genotypes but it had little effect on the P-resistant genotypes.