32个切花菊品种的耐低磷特性

Abstract

Cut chrysanthemum( Chrysanthemum × moriflorum Ramat.) is one of the most important ornamental plants in cut flower market all over the world. Phosphorus is a principal limited factor for plant growth,more than 90% of the added fertilizer phosphorus may rapidly be transformed to phosphorus forms that are not easily available to plants. Due to low natural phosphorus and high fixation capacity,a heavy dose of phosphorus is needed to achieve high production. Developing cultivars with tolerance to phosphorus deficiency may represent a more sustainable solution than sole reliance on fertilizer application. The possibility of exploiting genotypic differences in absorption and utilization of phosphorus to improve efficiency of phosphorus fertilizer use or to obtain higher productivity on phosphorus deficient soils has received considerable attention in recent years. In this study,to assess genotypic variation of cut chrysanthemum for tolerance to phosphorus deficiency,32 cultivars of cut chrysanthemum were screened and evaluated for tolerance to low phosphorus using sand culture at seedling stage with two treatments of low phosphorus( 15 μmol / L) and normal phosphorus( 300 μmol / L) in the Chrysanthemum Germplasm Resource Preserving Centre,Nanjing Agricultural University,China. The results showed that there existed evident genotype differences in different cultivars of cut chrysanthemum in tolerant ability to low phosphorus stress. Among all the characters studied,relative plant dry weight( low phosphorus supply / normal phosphorus supply), relative phosphorus content and relative phosphorus accumulation demonstrated significant genotypic variation( the CV was 12. 14%,20. 99% and 26. 41%,respectively). Moreover,correlation analysis showed that there were significant positive correlations between relative plant dry weight and relative phosphorus content,between relative plant dry weight and relative phosphorus accumulation,and between relative phosphorus content and relative phosphorus accumulation( P0. 01),the correlative coefficients are 0. 3067,0. 7391 and 0. 8258 respectively. Therefore,relative plant dry weight,relative phosphorus content and relative phosphorus accumulation were suggested as screening indexes of cut chrysanthemum on tolerance to low phosphorus stress. A comprehensive evaluation of low phosphorus tolerance of 32 cultivars was made by using hierarchical clustering analysis. Clustering analysis showed that 32 cultivars could be divided into extremely low phosphorus tolerant,low phosphorus tolerant,moderately low phosphorus tolerant,low phosphorus sensitive and extremely low phosphorus sensitive group respectively. Among 32 tested materials,the tolerant ability to low phosphorus stress of Nannongyinshan is higher than other cultivars, belonging to extremely low phosphorus tolerant cultivar; T1102, Nannongyupan, Nannonggongxun and Nannongbaixue are low phosphorus tolerant cultivars; Nannongyuzhu, Nannongjinrong,Nannongjindie,Nannongzichun,Nannongyuegui,huanghanju,Monalisa Yellow,Noa Yellow,Monalisa Rosy and Jinba are low phosphorus sensitive cultivars; the tolerant ability to low phosphorus stress of Nannonghongfeng, Nannongxiangbin and Youxiang are lower than other cultivars,these cultivars are extremely low phosphorus sensitive genotypes; the others are moderately low phosphorus tolerant cultivars. Efficient genotypes with the desirable characteristics can be used directly in advance field trials or in breeding programs to cope phosphorus deficiency.