海岛棉氮高效品种筛选与氮效率综合评价

Screening of Nitrogen High-Efficiency Varieties and Comprehensive Evaluation of Nitrogen Efficiency of Sea Island Cotton

为筛选氮高效海岛棉品种,补充收获期筛选指标,完善棉花氮效率评价体系,以近20年来育成的12个海岛棉品种为供试材料,设置低氮(0 kg/hm^(2),N_(0))、中氮(240 kg/hm^(2),N_(1))和高氮(480 kg/hm^(2),N_(2))3个氮肥处理,利用相关性分析、主成分分析和隶属函数分析综合评价海岛棉氮效率类型,筛选出氮高效海岛棉品种,确定收获期氮高效海岛棉品种筛选的评价指标。结果表明,不同氮肥水平下,供试海岛棉品种大部分指标变异系数均大于10%,将19个评价指标进行主成分分析,N_(1)和N_(2)水平下前4个主成分累计贡献率分别为86.68%和88.03%,其中株高、果枝数、茎叶生物量、生殖器官生物量等12个指标在4个主成分中占较大比重,并且指标间呈显著(P<0.05)或极显著(P<0.01)正相关。根据主成分综合得分、氮效率综合评价值与皮棉产量,筛选出1个氮高效品种、3个氮中效品种和3个氮低效品种。综上所述,确定棉城10号为氮高效品种,并得出SPAD、生殖器官生物量、生殖器官氮积累量、地上部总氮积累量、单株结铃数、籽棉产量、皮棉产量和氮肥农学利用率可作为氮高效品种筛选的核心指标。

In order to screen nitrogen-efficient sea island cotton varieties,supplement the harvest screening indexes and improve the cotton nitrogen efficiency evaluation system,three nitrogen fertilizer treatments of low nitrogen(0 kg/ha,N_(0)),medium nitrogen(240 kg/ha,N_(1))and high nitrogen(480 kg/ha,N_(2))were set up to comprehensively evaluate the type of nitrogen efficiency of the sea island cotton,screen out nitrogen-efficient sea island cotton varieties,and determine the evaluation indexes for screening nitrogen-efficient sea island cotton varieties in harvesting period by correlation analysis,principal component analysis and subordinate function analysis using 12 sea island cotton varieties bred in the past 20 years.The results showed that the coefficient of variation of most of the indicators of the sea island cotton varieties for testing under different nitrogen fertilizer levels were greater than 10%,and the 19 evaluation indicators were subjected to principal component analysis.Under N_(1) and N_(2) levels,the cumulative contribution rate of the four principal components were 86.68%and 88.03%,respectively.Among the four principal components,12 indicators,such as plant height,number of fruiting shoots,stem and leaf biomass,reproductive organ biomass,etc,accounted for a large proportion of the four principal components,and the indicators were significant(P<0.05)or extremely significant(P<0.01)positive correlation.Based on the comprehensive score of the principal components,the comprehensive evaluation value of nitrogen efficiency and lint yield,one nitrogen-efficient variety,three nitrogen-medium-efficient varieties and three nitrogen-low-efficient varieties were screened out.In summary,Miancheng 10 was identified as a nitrogen-efficient variety,and it was concluded that SPAD,reproductive organ biomass,reproductive organ nitrogen accumulation,total aboveground nitrogen accumulation,number of bolls per plant,seed cotton yield,lint yield,and nitrogen fertilizer agronomic utilization rate could be used as the core indexes for the screening of nitrogen-efficient varieties.