燕麦苗期性状对低氮胁迫的响应及耐低氮种质筛选

Response of seedling traits to low nitrogen stress and selection of low nitrogen tolerance germplasm of oat

为明确低氮胁迫对燕麦(Avena sativa)苗期生长的影响,选育耐低氮能力强的燕麦种质,本研究采用苗期水培法,分析了19份燕麦种质资源在常规氮(2 mmol·L^(-1)NH_(4)NO_(3))和低氮(0.2 mmol·L^(-1)NH_(4)NO_(3))处理下的生物量及耐低氮系数,初步筛选出5份耐低氮种质和5份低氮敏感种质。进一步复筛测定10份燕麦种质资源的叶绿素含量、生物量和根系形态构型等11项指标。结果表明:低氮胁迫下,植株茎叶干重、株高、叶片SPAD值显著降低(P<0.05),根干重、根冠比、根体积、根表面积和根尖数显著增加。结合方差分析、主成分分析和相关性分析得出,株高、茎叶干重、根干重、根表面积和根尖数可作为评价燕麦低氮耐受性的指标。根据耐低氮综合评价值(D),筛选出2个耐低氮种质ZY004067和ZY004068,3个氮敏感种质ZY004085、ZY004101和ZY004093。

To clarify the effects of low nitrogen stress on oat seedling growth,and select oat germplasm with high tolerance to low nitrogen.In this study,19 oat germplasm resources were used as materials to analyze the biomass and low nitrogen tolerance coefficient of oat under normal nitrogen(2 mmol·L^(−1) NH_(4)NO_(3))and low nitrogen(0.2 mmol·L^(−1) NH_(4)NO_(3))conditions by hydroponic method at the seedling stage.Per the low nitrogen tolerance coefficient of straw dry weight and plant dry weight,5 low nitrogen tolerant germplasm resources and 5 low nitrogen sensitive germplasm resources were screened.And 11 indexes including chlorophyll content,biomass,and root morphology of 10 oat germplasm resources were further determined by double-screening.The results demonstrated that under low nitrogen stress,straw dry weight,plant height,and leaf SPAD values were significantly decreased(P<0.05),while root dry weight,root-shoot ratio,root volume,root surface area,and root tip number were significantly increased(P<0.05).Variance analysis principal component analysis and correlation analysis showed that plant height,straw dry weight,root dry weight,root surface area,and root tip number could be used for evaluating the low nitrogen tolerance of oats.Per the comprehensive evaluation value of low nitrogen tolerance(D),two low nitrogen tolerance germplasms ZY004067 and ZY004068,and three nitrogen sensitive germplasms ZY004085,ZY004101,and ZY004093 were screened.