甘薯苗期耐低磷基因型筛选及磷效率综合评价

Screening of low phosphorus tolerance genotypes and comprehensive evaluation of phosphorus efficiency in sweetpotato at seedling stage

以63份不同基因型甘薯品种(系)为材料,采用水培试验,设置低磷胁迫(0.01 mmol·L^(-1)KH_(2)PO_(4))和正常施磷(1 mmol·L^(-1)KH_(2)PO_(4))处理,调查并比较不同磷水平下63个品种(系)甘薯苗期地上部干质量(m_(S))、根干质量(m_(R))、总干物质增加量(Δm)、蔓长(l_(V))、根长(l_(R))、根冠比(R)、地上部磷素积累量(m_(SP))、根系磷素积累量(m_(RP))、地上部磷含量(w_(SP))、地上部磷变化量(Δw_(SP))、根磷含量(w_(RP))、磷素生理利用效率(E)12个性状表征值的差异.通过相关性分析、因子分析、模糊隶属函数法以及聚类分析法对不同甘薯品种进行耐低磷性评价和基因型差异分类.结果表明:低磷胁迫下,不同甘薯材料苗期各性状均受到不同程度的影响;m_(R)、m_(RP)、m_(SP)、w_(SP)和Δw_(SP)可作为鉴定耐低磷甘薯基因型的苗期筛选指标.以耐低磷性综合评价值(D)进行聚类分析,将供试甘薯材料划分为耐低磷基因型、中度耐低磷基因型、低度耐低磷基因型和不耐低磷基因型,筛选出徐薯34、红优、坦桑尼亚和苏薯8号4个耐低磷基因型甘薯.供磷水平显著影响甘薯苗期各性状指标,基于甘薯种质间农艺性状、磷素积累量和磷素生理利用效率的差异,结合4种分析方法,可以准确评价甘薯种质资源苗期磷效率状况,为甘薯耐低磷生理机制研究和磷高效品种的选育提供理论依据.

63 sweetpotato varieties(lines)with different genotypes were used as materials,and the hydroponics experiment was conducted.The treatments of low P stress(0.01 mmol·L^(-1) KH_(2)PO_(4))and normal P application(1 mmol·L^(-1) KH_(2)PO_(4))were set up.Twelve characteristic values,including the shoot dry biomass(m_(S)),root dry biomass(m_(R)),plant dry biomass increase(Δm),vine length(l_(V)),root length(l_(R)),root/shoot ratio(R),shoot P accumulation(m_(SP)),root P accumulation(m_(RP)),shoot P content(w_(SP)),variation of shoot P content(Δw_(SP)),root P content(w RP),and P physiological utilization efficiency(E),were used to evaluate the low P tolerance of sweetpotato varieties and classify genotypic differences by using correlation analysis,factor analysis,comprehensive membership function,and cluster analysis.All characters of different sweetpotato materials at seedling stage were affected to varying degrees under low P stress.The m_(R)、m_(RP)、m_(SP)、w_(SP) and Δw_(SP) can be used as screening indicators for identifying low P tolerant sweetpotato genotypes at seedling stage.According to the comprehensive evaluation value(D)of low P tolerance,the tested sweetpotato materials were classified into low P tolerance genotype,moderately low P tolerance genotype,minutely low P tolerance genotype,and low P sensitive genotype.Four low P tolerant genotypes of sweetpotato including Xushu 34,Hongyou,Tanzania and Sushu 8 were screened.The level of P supply significantly affected the indexes of various characters of sweetpotato at seedling stage.Based on the differences of agronomic characters,P accumulation and P physiological utilization efficiency among sweetpotato germplasm,combined with four analysis methods,the P efficiency of sweetpotato germplasm resources at seedling stage can be accurately evaluated.It provides theoretical basis for the study of physiological mechanism of low P tolerance and the breeding of varieties with high P utilization efficiency of sweetpotato.