| Wild soybean is a national secondary protected wild plant.It is meaningful to study the distribution and diversity of wild soybean for better understanding,protection and rational application.In order to investigate the population distribution of wild soybean in 10 cities in Jiangsu Province,a combination of sample method and tracing method were used in this study.Depend on the basically understanding of the distribution of wild soybean in Jiangsu Province,the population diversity of wild soybean in 7 cities with different habitats was investigated.Meanwhile,the anatomical structure of stems and leaves of different populations of wild soybean was studied by paraffin sectioning.In addition,the genetic diversity of 27 wild soybean populations in 13 cities in Jiangsu Province was analyzed by SSR molecular markers.The following results were obtained;1.The results of population diversity indicated that the plants in the wild soybean population in Jiangsu Province belong to 137 species,83 genera and 50 families.The most common species in the wild soybean community is Compositae,with 28 species,followed by Gramineae,with 17 species and the main companion plants are Conyza canadensis,Digitaria sanguinalis,Phragmites communis and Setaria viridis,The composition of companion plants in wild soybean populations in Suzhou and Wuxi is similar,but the wild soybean populations in Suzhou are more abundant.Among the wild soybean populations in Nanjing,there are plants that are not found in other areas such as Gynostemma pentaphyllum,Oplismentls undulatifoliusfolius,Menispermum dauricum,and Pteris ensiformis.The open areas of Yangzhou are mostly wasteland,and the associated plants are strong adaptable plants,such as Digitaria sanguinalis,Conyza canadensis,Erigeron annuus,and Setaria viridis.In Huai’an,there are two kinds of plants,Adenocaulon himalaicum and Pennisetum alopecuroides,which are not found in other areas.At the same time,it was found that the distribution of wild soybean in Xuyi was less.The composition of wild soybean varies greatly in Lian Yungang because of the different environments,such as seashore,mountain and wetland.The main companion plant in the open field is Setaria viridis.The main companion plant in the gully is Conyza canadensis.The importance values of Setaria viridis,Ligustrum quihoui and Digitaria sanguinalis in the shrub are higher.The highest value of wild soybean in the open area of Xuzhou is the dominant species,and Humulus scandens and Erigeron annuus are the sub-optimal species;the wild soybean in the gully are competitive with Conyza canadensis;the wild soybean in the shrub is highly competitive with Digitaria sanguinalis,but the wild soybean is only slightly dominant2.Anatomical studies have shown that there are differences in the anatomical structure of wild soybean stems in diverse habitats of different regions.In the wild soybean population with fierce competition,the length and width of the vascular bundle,as well as the proportion of pith in the cross-section of the stem of wild soybean were significantly increased.The changes of wild soybean stem in different regions did not show obvious regularity,because in different regions,the habitats are diverse.Temperature,humidity,soil and other factors are not solely affecting the growth of wild soybean but working together.In the investigation,the shape of the terminal leaflets in the wild-type three-leaf compound leaves of the wild soybean is mainly oval,elliptical,oblong,and lanceolate.The anatomical features are expressed as:in the area with large plant density population of wild soybean,the palisade tissue thickness,sponge tissue thickness and main vein thickness of wild soybean leaves were larger than those of in open fields3.The results of 16 pairs of SSR primers showed that the number of polymorphic loci in wild soybean in Jiangsu Province was 14 and the percentage of polymorphic loci was 87.5%This indicated that the wild soybean in Jiangsu Province had higher differentiation and genetic diversity.From the genetic distance and genetic similarity,it can be concluded that the relationship of wild soybean between Suqian and Yangzhou is the closest,while Suzhou and Zhenjiang are the oppositeThis was the first time that the population,morphology and genetic diversity of wild soybean in Jiangsu Province were systematically studied.The research has certain reference value and guiding significance for the distribution,diversity research,and protection of wild soybean germplasm resources in Jiangsu Province. |
