江南地区牡丹引种综合性评价及孢粉学聚类分析

Comprehensive evaluation and palynological cluster analysis of introduced peony cultivars in Jiangnan region

  • 摘要: 目的 通过开展江南地区牡丹引种的综合性评价,并分析品种间的亲缘关系,为培育适宜江南地区栽培的牡丹品种提供理论依据。方法 运用层次分析法(AHP)对江南地区引种的33个牡丹品种资源进行实地调查,从观赏性、生长性状、生态适应性等方面对引种的33个牡丹品种进行评价,构建综合评价体系,并筛选出适应性强的牡丹品种,同时对牡丹花粉结构进行观察及聚类分析,确定品种间亲缘关系。结果 依据牡丹的特性,构建由目标层、约束层、标准层、最底层4个阶层组成的层次结构模型,并将其观赏性、生长性状和生态适应性作为综合性评价因子,构建合理的牡丹引种综合评价模型。在准则层中以生长性状的权重值最高,为0.5813,其因子层中的分支数权重值最高,为0.4960。将各品种的综合评价值分为4个等级,分别为Ⅰ、Ⅱ、Ⅲ、Ⅳ级,其中Ⅰ级优良品种有3个,分别为湘绣球、岛锦、林峰;Ⅱ级较优良品种有9个;Ⅲ级一般品种有18个;Ⅳ级较差品种有3个,分别为海黄、太阳、新云谷。通过扫描电镜观察发现,33个引种牡丹品种花粉均以单粒形式存在,多数为超长球形(极轴长/赤道轴长>2.00),极面观均为三裂圆形,萌发器官具3条孔沟,外壁纹饰以穴网状为主。基于花粉形态量化指标对引种的牡丹品种进行聚类分析,结果发现品种间多样性主要体现在花粉外壁纹饰,当欧式遗传距离为1.5时,可将其分为5个类群,其中类群Ⅰ有23个品种,类群Ⅱ有2个品种,类群Ⅲ有6个品种,类群Ⅳ、Ⅴ各有1个品种;当欧式遗传距离为5.0时,可将其分为2个类群,其中类群A有31个品种(包括类群Ⅰ、Ⅱ、Ⅲ),类群B有2个品种(包含类群Ⅳ、Ⅴ)。结论 在江南地区引种牡丹时可优先考虑牡丹的生长性状,其次是适应性和观赏性。Ⅰ级优良品种湘绣球、岛锦、林峰可大量引进作为主栽品种,Ⅱ级较优良品种可根据需求选择性引种,Ⅲ级和Ⅳ级品种表现较差,不建议引种。在引种牡丹中,海黄、日暮与其他品种亲缘关系较远,首案红与凤丹蓝亲缘关系较近。

     

    Abstract: Objective This study aimed to conduct a comprehensive evaluation of introduced peony cultivars in Jiangnan region and analyze the genetic relationships among the introduced cultivars, so as to provide a theoretical basis for breeding peony cultivars adapted to local conditions.Method Field investigations on 33 introduced peony cultivars in the Jiangnan region were conducted using the analytic hierarchy process (AHP). The 33 introduced peony cultivars were evaluated from the perspective of ornamental value, growth traits, ecological adaptability and so on to establish a comprehensive evaluation system for screening peony cultivars of high-adaptability. Concomitantly, pollen morphology was observed, and cluster analysis was performed to determine genetic relationships among the cultivars.Result Based on the characteristics of peonies, a four-tiered hierarchical model was established, comprising the target layer, constraint layer, criterion layer, and base layer. By incorporating ornamental value, growth traits, and ecological adaptability as comprehensive evaluation factors, an evaluation model for introduced peonies. In the criterion layer, the weight value of growth traits was the highest (0.5813), while in the factor layer, the weight value of branch number was the highest (0.4960). The evaluated cultivars were classified into four grades based on comprehensive assessment scores: GradeⅠ, Grade Ⅱ, Grade Ⅲ, and Grade Ⅳ. Three cultivars were rated as excellent cultivars in GradeⅠ: Xiangxiuqiu, Daojin and Linfeng; nine cultivars were rated as good cultivars in Grade Ⅱ; eighteen were rated as average cultivars in Grade Ⅲ; and three were rated as poor cultivars in Grade Ⅳ: Haihuang, Taiyang and Xinyungu. Scanning electron microscopy revealed that the pollen of 33 introduced peony cultivars occurred as single grains, most of which were prolate spheroidal (polar axis/equatorial axis > 2.00). In polar view, the pollen grains appeared trilobate-rounded, with three colporate germinal apertures, and the exine ornamentation was predominantly foveolate-reticulate. Cluster analysis based on quantitative indicators of pollen morphological characteristics revealed significant diversity in exine ornamentation patterns among the introduced tree peony cultivars. At a Euclidean genetic distance threshold of 1.5, the cultivars were classified into five groups: Group Ⅰwith 23 cultivars, Group Ⅱ with 2 cultivars, Group Ⅲ with 6 cultivars, and Groups IV and V each with one cultivar. At a Euclidean genetic distance threshold of 5.0, the cultivars were classified into two groups: Group A with 31 cultivars (including GroupⅠ-Ⅲ), and Cluster B with 2 cultivars (including Group Ⅳ-Ⅴ).Conclusion When introducing peony in Jiangnan region, the priority is considering growth traits, followed by adaptability and ornamental value. GradeⅠcultivars, Xiang Xiuqiu, Dao Jin and Lin Feng, are recommended for large-scale introduction as principal varieties. Grade Ⅱ cultivars with relatively good performance can be introduced based on demand, while Grade Ⅲ and Ⅳ cultivars with unsatisfactory performance and are not recommended for introduction. Among the introduced peony cultivars, Haihuang and Rimu are distantly related to the other cultivars, whereas Shouanhong and Fengdanlan are closely related.

     

/

返回文章
返回