【摘要】 籽粒机收是我国玉米实现全程机械化的瓶颈,而收获期籽粒含水量则是影响其机收效果的关键因素。加快成熟后期籽粒脱水速率是降低收获期籽粒含水量而不影响产量的有效方式。本研究以5个活秆成熟(SG)和5个非活秆成熟(NSG)自交系为对象,测定其籽粒、叶片和茎秆的含水量,计算其脱水速率。结果显示,活秆成熟自交系的收获期籽粒含水量和叶片含水量均高于非活秆成熟自交系,而茎秆含水量在活秆成熟和非活秆成熟两类自交系间没有明显差异。相关性分析显示叶片脱水速率和籽粒脱水速率呈显著正相关(相关系数0.756,P<0.05)。根据衰老启动标记基因ZmSee1的表达水平,分析叶片衰老启动时间与籽粒脱水速率的相关性,表明:在非活秆成熟的5个自交系中,LH196、PHM10和PH207的ZmSee1基因表达峰值出现在授粉后第4 d,DK517M和Lx9801的ZmSee1基因表达峰值出现在授粉后第8 d;而在活秆成熟的5个自交系中,ZmSee1基因的表达峰值均出现在授粉后第16 d。相关性分析发现,叶片衰老启动时间和籽粒脱水速率之间存在显著负相关,相关系数为-0.733(P<0.05)。更多还原

【Abstract】 Kernel mechanical harvesting is the bottleneck of the whole mechanization of maize in China. The grain moisture at harvest stage is a key factor influencing the mechanical harvest effect. Increasing the dehydration rate after physiological maturity is an effective way to reduce grain moisture at harvest stage without affecting production. In this study, five stay green(SG) inbred lines and five non-stay green(NSG) inbred lines were used as test materials. The moisture content of kernels, leaves and stem were measured and then the dehydration rate was calculated. The results showed that the moisture of kernels and leaves in SG inbred lines were higher than that of NSG inbred lines. There was no significant difference in stem moisture between SG and NSG inbred lines. Correlation analysis showed that the dehydration rate of leaves was positively related to the dehydration rate of kernels(correlation coefficient as 0.756, P<0.05). According to the expression level of senescence initiation marker gene ZmSee1, the correlation between senescence initiation time and kernel dehydration rate was analyzed. In the five NSG inbred lines, the peak expression level of ZmSee1 gene in LH196, PHM10 and PH207 occurred on the 4 th day after pollination, while the peak expression level of ZmSee1 gene in DK517 M and Lx9801 occurred on the 8 th day after pollination. In the five SG inbred lines, the peak expression level of ZmSee1 gene occurred on the 16 th day after pollination. Correlation analysis showed that the leaf senescence initiation time was negatively related to the dehydration rate of kernel with the correlation coefficient as-0.733(P<0.05).更多还原