低磷胁迫下玉米苗期根系特征及优良材料筛选

Root Characteristics of Maize Seedlings and Selection of good Inbred Lines Under Low-Phosphorus Stress

【目的】鉴定低磷胁迫下玉米苗期的根系性状特征,筛选耐低磷的优良自交系,为开展玉米磷高效品种选育提供理论参考和材料基础。【方法】在水培营养液条件下,按照低磷和正常处理,培养105份玉米自交系15天,测量苗期的14个根系性状,并计算其综合耐低磷系数。【结果】在低磷条件下玉米自交系多数根系性状都显著增加,仅有平均根直径和冠根数及鲜重减少。根据综合耐低磷指数分析,耐低磷自交系中属于Non-Reid群的居多,低磷敏感的自交系中属于Reid群的自交系居多,并从中分别筛选出了10个极端耐低磷和敏感型玉米自交系。【结论】在低磷胁迫下,玉米通过增加根系发育响应低磷胁迫,且材料之间存在着丰富的变异,表明通过遗传改良可以提高玉米耐低磷特性。

[ Objective ] It aims to identify root characters within period of maize seedling emergence under low phosphorus stress, screengood inbred lines of low-phosphorus resistance, provide theoretical reference and material basis for the breeding of phosphorus high efficiency maize varieties. [ Method ] With hydroponic nutrient solution,low phosphorus ＆ normal treatment, 105 maize inbred lines are cultured for 15days; 14 root characters are measured at period of seedling emergence; a comprehensive coefficient of low-phosphorus resistance is calculated. [ Result ] Most root characters of maize inbred lines are significantly increased under low-phosphorus conditions, with only average rootdiameter and crown number and fresh weight reduced.According to the analysis of comprehensive index of low-phosphorus resistance, most resistant and sensitive lines are respectivelyderived from non-Reidgroup and Reidgroup, among which 10 maize inbred lines are respectively screened out from the extremely low-phosphorus resistancegroup and sensitivegroup. [ Conclusion] Maize responds to low-phosphorus stress by increasing rootdevelopment with plentifulgenetic variation, which suggests it is practicable to improve maize＇s characteristic of high phosphorus efficiency throughgenetic improvement.