文冠果不同种质资源的叶片解剖结构分析及抗旱性评价

  目的  评价文冠果Xanthoceras sorbifolium不同种质资源在干旱地区的适应能力,为干旱、半干旱地区筛选抗旱文冠果种质提供依据。  方法  以内蒙古自治区通辽市文冠果种质资源圃内前期筛选的200份丰产型文冠果种质资源的叶片为材料,通过制作石蜡切片对叶片解剖结构进行观测,测定了叶片厚度、栅栏组织厚度、海绵组织厚度、蜡质层厚度等13个与文冠果抗旱性相关的指标,并基于因子分析、聚类分析和隶属函数分析的方法评价不同文冠果种质资源的抗旱性。  结果  文冠果叶片解剖结构指标之间具有显著的相关性,基于因子分析法提取了4个公因子,对变异的累计贡献率达89.99%,涵盖了13个指标的大部分信息,对文冠果抗旱性的影响程度依次为:F₁ (厚度指数因子)＞F₂ (组织指数因子)＞F₃ (表皮占比因子)＞F₄ (蜡质层占比因子)。  结论  F₁公因子中载荷较大的上/下表皮厚度、栅栏组织厚度和导管直径可作为评价文冠果抗旱性的主要指标。筛选出的90份抗旱型种质资源能兼顾丰产和节水抗旱的优点,可为干旱地区提供适宜的种质材料。图1表6参32

Leaf anatomical structure and evaluation of drought resistance of different germplasm resources of Xanthoceras sorbifolium

  Objective  This study aims to evaluate the adaptability of different germplasm resources of Xanthoceras sorbifolium in arid areas, so as to provide a basis for screening drought-resistant germplasm resources for arid and semi-arid areas.   Method  The leaves of 200 high-yield X. sorbifolium germplasm resources were collected in Tongliao Germplasm Resources Nursery in Inner Mongolia Autonomous Region. The anatomical structure of leaves was observed by making paraffin section, and 13 indexes related to drought resistance were measured, including leaf thickness, palisade tissue thickness, sponge tissue thickness and wax layer thickness. The drought resistance of different germplasm resources was evaluated by factor analysis, cluster analysis and membership function analysis.   Result  The anatomical structure indexes of leaves showed significant correlation. Based on factor analysis, 4 common factors were extracted, and the cumulative contribution rate to variation was 89.99%, basically covering most of the information of the 13 indicators. The degree of influence on drought resistance ranging from large to small was as follows: F₁ (thickness index factor), F₂ (tissue index factor), F₃ (epidermal proportion factor), and F₄ (wax layer proportion factor).   Conclusion  The thickness of upper/lower epidermis, thickness of palisade tissue and vessel diameter, which are the most important factors in F₁, can be used as the main indicators for drought resistance evaluation of X. sorbifolium. The selected 90 drought-resistant germplasm resources, with advantges of high-yield, water-saving and drought-risistant, could provide materials for the breeding of drought-resistant X. sorbifolium. [Ch, 1 fig. 6 tab. 32 ref.]