引进国外的野生甜瓜种质资源果实形态多样性分析

【目的】探究从国外引进的野生甜瓜种质资源的遗传多样性和遗传关系,为野生甜瓜种质资源的评价、分类和高效利用提供参考依据。【方法】以国外引进的100份野生甜瓜种质为材料,采集果实性状数据用于分析野生甜瓜种质资源的遗传多样性,另以我国的薄皮甜瓜、厚皮甜瓜、‘看瓜’和野生甜瓜为参照,分析国外引进野生甜瓜与我国甜瓜种质资源之间的亲缘关系。【结果】国外引进野生甜瓜果实的质量性状和数量性状平均多样性指数分别为0.98和1.79,显示出果实的数量性状具有更丰富的多样性;聚类分析表明,在欧氏距离3.0处可将国外引进野生甜瓜种质资源分为野生和半野生2个类群,在半野生类群中又可分为2个亚群,其中亚群ⅰ包含了参照种质薄皮甜瓜,亚群ⅱ则包含了参照种质厚皮甜瓜。【结论】引进的野生甜瓜种质资源具有丰富的遗传多样性,以果实的数量性状最为突出,并可以分为野生和半野生2种类型,呈现出野生甜瓜向栽培甜瓜驯化的聚类结构,暗示这些甜瓜野生种质在栽培甜瓜的起源与驯化过程中起到重要作用。

不同种类切花菊观赏性状的形态多样性分析

为了给切花菊品种分类以及新品种选育提供理论支持,将291份切花菊资源分为4类(独头夏菊,独头秋菊,多头夏菊,多头秋菊),共调查观赏性状18个,并对其进行单因素方差显著性分析;同时,对各性状的变异系数以及正态性分布进行比较。结论认为:4类切花菊的花色、茎粗度、叶长、叶宽的差异极显著,叶柄角度差异显著,植株高度、茎强度、叶片长宽比、叶色差异不显著。所有类型的切花菊观赏性状变异系数在0.15~1.66之间,不同部位性状的变异系数的表现为花部性状>茎部性状>叶部性状;说明切花菊存在较丰富的形态多样性。正态分布统计结果:所有切花菊的质量性状均不符合正态分布,而数量性状中独头秋菊的花径大小、茎粗、植株高度、舌状花瓣数符合正态分布,其余均符合偏态分布;独头夏菊除侧芽发生程度以外,其余均符合正态分布;多头秋菊除节间长度外,其余均符合偏态分布;多头夏菊除叶柄角度和节间长度外,其余均符合正态分布。

Morphological Diversity Analysis of Red-seed Watermelon (Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao) Germplasm Resources

[Objective] This study aimed to analyze the morphological diversity of red- seed watermelon （Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao） germplasm resources. [Method] Multiple cluster analysis and principal components analysis on the morphological traits of 51 red-seed watermelon germplasm resources were carried out. [Result] The coefficient of variations （CVs） of 39 morphological traits in 51 red-seed watermelon idioplasm resources ranged from 5.37% to 66.95%, with an average of 22.87%. The average of Shannon diversity information indices was 1.55. Among them, the Shannon diversity information index of seed length was the highest （2.16） and that of seed shell figure pattern was the lowest （0.32）. In ad- dition, the morphological diversity information indices of quantity characters were higher than that of quality characters. The principal components analysis revealed that the variance contribution rates of the first, second and third principal compo- nents were 19.49%, 15.32% and 9.55%, respectively. Cluster analysis divided the 51 materials into three broad branches based on the morphological traits. There was only one material in the fist branch and two in the second branch, and all the three materials were wild. The other 48 materials were divided into the third branch and all of them were cultivars. [Conclusion] This study provided a theoretical basis for the protection and utilization of red-seed watermelon resources.

Genetic Diversity and Interrelationship Among Mulberry Genotypes

Fourteen morphometric traits were used to examine the genetic divergence of 25 mulberry （Morus spp.） genotypes from varied agroclimatic conditions of India. Wide variation was observed for all the traits. The genotypes irrespective of their place of collection were grouped into 10 different clusters. Seven accessions, that is, Baragura-2, Gorabandha-2, Kalimpong, Herbertpur, Kollegal, Resham majri-7, and UP-14 each a cluster of unique entries will be of useful for genetic resources. Nevertheless, the correlation and path analysis suggest the direct selection of lamina length, fresh leaf weight, leaf area, and single leaf weight will be rewarding for mulberry leaf yield improvement.

A Preliminary Phylogenetic Analysis of Luidia (Paxillosida: Luidiidae) from Chinese Waters with Cytochrome Oxidase Subunit I (COI) Sequences

Luidia Forbes （Paxillosida： Luidiidae） are common soft bottom sea stars with 49 described species. Because of substan- tial morphological diversity, the taxonomy of the genus is complex and hasn＇t been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of tyro- chrome oxidase subunit I （COI） gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetie relationships. The molecular phy- logeny exhibited three main clades, each with strong bootstrap support： Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species （L. quinaria von Martens, L. yesoensis Goto, L. ehangi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray） from Chinese waters; and Clade C including L. maculata Miiller ＆ Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alter- nata-Group assigned by D6derlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to rec- ognize them as separate species. Cryptic species may exist in ＇Luidia quinaria＇ from the Yellow Sea and the Sea of Japan. Meaning- ful morphological characters need further investigation in Luidia.

Thin-Plate Spline Analysis of Diversity in Field Populations of Codling Moth, Cydia pomonella L. （Lep., Tortricidae） in North West of Iran

In order to study morphological diversity of codling moth, Cydia pomonella （L.） using thin-plate spline analysis, nine geographical populations from four north western provinces of Iran namely East Azarbayjan, West Azarbayjan, Ardebil and Zandjan were collected during 2003 and 2004. 575 and 564 images were prepared from fore and hind wings, respectively. Then 15 and 11 landmarks were determined from fore and hind wings, respectively. With transforming of landmark＇s two dimensional coordinate data into partial warp scores, 26 and 18 scores were generated for fore and hind wings, respectively. Cluster analysis based on wing shape variables using Ward＇s algorithm assigned nine geographical populations into two groups. The pattern of grouping based on fore and hind wings was different in both sexes. Principal component analysis revealed discrimination between geographic populations and confirmed the result of cluster analysis. Among environmental parameters, wind speed showed the highest correlation with wing shape variables. Non significant correlation was observed between geographic and morphological distance matrices as revealed by Mantel test.