中国农业科学 ›› 2017, Vol. 50 ›› Issue (17): 3311-3322.doi: 10.3864/j.issn.0578-1752.2017.17.006

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

不同基因型苦荞苗期抗旱性综合评价及指标筛选

路之娟1,张永清1,2,张楚1,刘丽琴1,杨春婷1

 
  

  1. 1山西师范大学生命科学学院,山西临汾 0410042山西师范大学地理科学学院,山西临汾 041004
  • 收稿日期:2017-04-10 出版日期:2017-09-01 发布日期:2017-09-01
  • 通讯作者: 张永清,E-mail:yqzhang208@126.com
  • 作者简介:路之娟,E-mail:luzhijuan1992@126.com
  • 基金资助:
    国家自然科学基金(31571604)

Comprehensive Evaluation and Indicators of the Drought Resistance of Different Genotypes of Fagopyrum tataricum at Seedling Stage

LU ZhiJuan1, ZHANG YongQing1, 2, ZHANG Chu1, LIU LiQin1, YANG ChunTing1   

  1. 1College of Life Sciences, Shanxi Normal University, Linfen 041004, Shanxi; 2 College of Geographical Sciences, Shanxi Normal University, Linfen 041004, Shanxi
  • Received:2017-04-10 Online:2017-09-01 Published:2017-09-01

摘要: 【目的】苦荞不仅具有丰富的营养价值和药用价值且具有耐冷凉、耐瘠薄、适应性强等生理特性,不同苦荞品种间的抗旱性差异显著,探讨苦荞苗期耐旱特性,筛选耐旱基因型材料及耐旱性鉴定指标并建立耐旱性数学评价模型,不仅能够为品种耐旱性评价与品种筛选奠定基础,更为黄土高原冷凉地区的种质选育提供理论依据。【方法】采用苗期沙培方式,设置正常供水CK和干旱胁迫DS两个处理,对9份不同苦荞品种在不同处理下的株高、茎粗、叶面积等农艺性状及根系活力、根系酶活性等生理指标进行测定。利用隶属函数法、主成分分析与聚类分析对各苦荞品种耐旱能力进行综合评价,并用逐步回归分析建立最优回归方程进而实现对苦荞耐旱能力的预测与鉴定。【结果】干旱胁迫对苦荞各指标均有显著影响,差异性分析结果表明,苦荞苗期地上部指标、根系干重、根系活力、根系形态指标、可溶性蛋白含量、相对含水量、叶绿素含量、Fm 和 Fv/Fm等指标与对照相比均明显下降;而根系酶活性、MDA含量、可溶性糖、游离脯氨酸含量、Fo与对照相比,表现为升高,且耐旱型品种的根冠比也表现为升高,中间型和不耐旱品种则表现为下降。主成分分析将21个单项指标转化为3个相互独立的综合指标(累计贡献率达87.30%),且第1主成分主要反映的是生物量、根系形态、叶片荧光参数等信息;第2主成分反映的是植株根系活力、根系酶活性和根系渗透调节物质等信息;第3主成分反映的是植株地上部形态及部分叶片和根系生理特性的相关信息。聚类分析将9个苦荞基因型划分为3类,分别为耐旱型、中间型和不耐旱型。为了对各基因型的耐旱能力进行预测并建立数学评价模型,将D值作因变量,各指标耐旱系数作自变量进行逐步回归分析。结果分析表明,通过建立最优回归方程,筛选出株高、茎粗、根冠比、根系活力、最大根长、MDA、Fo及水势等8项对苦荞耐旱能力有影响的指标,并且9个苦荞基因型的苗期耐旱能力预测值与D值极显著相关(R2=0.988**),表明用此方程对苦荞抗旱特性进行预测具有一定的准确性及高效性,进而在苦荞抗旱特性的鉴定工作中如果有选择的测定上述指标,可使鉴定工作简单化。【结论】干旱胁迫对苦荞苗期各指标均有显著影响。通过聚类分析图得出参试品种分为3大类型,即迪庆苦荞、西农9909和奇台农家品种为耐旱型品种;广苦1号、黔苦6号、云荞1号为中间型品种;多元苦荞、黑丰1号和西荞1号为不耐旱品种。确定了苗期耐旱能力预测值与D值极显著相关(R2=0.988**),筛选出株高、茎粗、根冠比、根系活力、最大根长、MDA、Fo及水势等指标,可作为苦荞抗旱特性快速鉴定的指标。

关键词: 苦荞, 抗旱指标筛选, 主成分分析, 聚类分析, 回归分析

Abstract: 【Objective】Fagopyrum tataricum not only has rich nutritional and medicinal values, but also has great physiological characteristics such as relatively high tolerance and strong adaptation ability to cold and barren conditions. There is a significant difference in resistance to drought stress among different genotypes of F. tararicum. Study of drought resistance characteristics of F. tataricum, screening of the materials of high tolerance genotypes and identification of indicators of drought resistance, and building a mathematic model for appraising the drought resistance not only can provide a foundation for evaluating the drought resistance and selection of genotypes, but also can provide a theoretical basis for germplasm breeding in cold areas of Loess Plateau. 【Method】Multiple indices of seedlings, including agronomic traits and physiological characteristics, were measured in the normal supply and drought stress with nine F. tataricum genotypes. Subordination function method, principal component analysis and clustering analysis were used to synthetically evaluate the drought resistance of different F. tataricum genotypes. Moreover, stepwise regression analysis was used to establish the optimal regression equation that could forecast and identify the drought resistance ability of F. tataricum. 【Result】Drought stress has an obvious effect on the indexes of F. tataricum at seedling stage. Results of difference of testing indices showed that the overground index, root dry weight, root activity, root morphology index, soluble protein contents, relative water content, chlorophyll content and leaf fluorescence parameters under drought stress were obviously decreased compared with the control group. Compared with the control group, drought stress not only resulted in the decreases of aboveground and root characteristics, root activity, soluble protein contents, leaf relative water and chlorophyll content, Fm and Fv/Fm, but also resulted in the increase of the activities of superoxide dismutase (SOD) and peroxidase (POD), the contents of malonaldehyde (MDA) and soluble sugar, and leaf Fo. Besides, the root-shoot ratio of drought tolerance genotypes showed a rising trend, while the intermediate and drought-intolerant genotypes showed a declining trend. The principal component analysis turned 21 single indices into three independent comprehensive indices (accumulative contribution of 87.30%). The principal component 1 mainly reflected the information of biomass, root morphology, and leaf fluorescence parameters etc. The principal component 2 mainly reflected the information of root activity, root enzyme activity and osmotic adjustment substances etc. While the principal component 3 mainly reflected the information of aboveground morphology, partial leaf and root physiological characteristics. Nine F. tataricum genotypes were divided into three categories by clustering analysis: drought-tolerant type, middle type, and drought-intolerant type. In order to predict the drought resistance of each genotype and build a mathematical evaluation model, D values and drought tolerance index of various indexes were taken as the dependent variable and independent variable, respectively, for the stepwise regression analysis. By establishing an optimal regression equation, eight influential indices for drought resistance, including plant height, stem diameter, root-shoot ratio, root activity, main root length, MDA content, Fo, and leaf relative water content, were selected. The predictive values of drought tolerance of nine F. tataricum had a significantly correlation with D values (R2=0.988**), which showed a certain accuracy and efficiency to forecast the F. tataricum drought-resistance by using this equation. And the identification work could become easier when measuring these indexes selectively. 【Conclusion】Drought stress has significant influence on each index during seeding stage of F. tataricum. According to the cluster trend diagram, the tested categories can be divided into three types: drought tolerance type (including Diqing kuqiao, Xinong 9909, Qitai farmers), intermediate type (including Guangku 1, Qianku 6 and Yunqiao 1), and non drought-intolerance type (including Duoyuan kuqiao, Heifeng 1 and Xiqiao 1). The study selected the nine indexes including plant height, stem diameter, root-shoot ratio, root activity, main root length, MDA content, Fo, and leaf relative water content, which could rapidly identify the drought resistance of F. tataricum, and the predictive values of drought tolerance is significantly correlated with D values (R2=0.988**).

Key words: fagopyrum tataricum, screening drought resistance index, principal component analysis, clustering analysis, regression analysis