Comparative Study On Morphology,physiology,yield And Quality Of Different Varieties Of Dioscorea Opposita Thumb

Yam(Dioscorea opposita Thunb.)is a division of Dioscorea a year or perennial herbaceous plants,cultivation has a long history in our country,in the long-term cultivation in the process of breeding all over the country formed a distinctive local varieties,medicine and food,in order to save and use high quality germplasm resources,many areas of different varieties of yam has carried on the introduction and breeding and germplasm nursery is established.In this experiment,the morphology,physiology,yield,quality and adaptability of ten Chinese yam cultivars planted in resource nursery of wenxian county agricultural science and technology research institute were compared,which laid a foundation for the introduction of high-quality Chinese yam cultivars and the evaluation and utilization of germplasm resources of different Chinese yam cultivars.The results are as follows:1.In terms of morphology,there was no significant difference in the overall growth of each variety except that Qinfeng Huai was weak;The leaf size of each variety was different,and the leaf size of Taiwanzi was the largest,which was obviously different from other varieties.The leaves of Qinfeng Huai and Taihe had already turned yellow in October.The number of veins in the leaves was 7 or 9.Stomatal density of leaves of all varieties was significantly different from that of the lower surface.The surface of rhizome of Tiegun has the characteristic rust stain,the surface of other varieties has no obvious difference,the rhizome of most varieties is long straight type.2.Physiologically,different varieties have different chlorophyll contents in their leaves.The highest content of chlorophyll is Hebeibang,while the lowest is Qinfeng Huai.The net photosynthetic rate of each variety was different,and the net photosynthetic rate of each variety was positively correlated with stomatal conductance and transpiration rate.3.In terms of yield,the highest yield per plant was Dahechangyu(626g per plant),and the lowest was Qinfeng Huai(246g per plant).The fresh weight of each variety was significantly different,but the dry weight of each plant was not significantly different.The highest discount rate was Tiegun as 35.34%,while the lowest was Dahechangyu as 14.71%.4.In terms of quality,the contents of nutritional and medicinal ingredients of different varieties are not the same,and the contents of nutritive ingredients of dioscoreae with and without skin are also different:(1)The difference of polysaccharide content among different varieties was significant,the content of polysaccharide of dioscoreae was higher than that of dioscoreae after peeling;The polysaccharide content of Qinfeng Huai was the highest as 111.61mg/g,and that of Hebeibang was the lowest containing 14.42mg/g.(2)The starch content was differenct between varieties,the highest was Taiwanzi as 175.45 mg/g,the lowest was Dahechangyu as 51.29 mg/g,starch content from high to low rank was Taiwanzi > Tiegun> Hebeibang > Qingfeng Huai > Pingyao > Guannan>Taihezhu>Niutuimi >Taigu > Dahechangyu.(3)There was a significant difference in the total protein content among the varieties.The total protein content of dioscoreae containing sink was higher than that without skin.Among the total protein content of yams containing or without sink,Tiegun were the highest,36.64mg/g with sink and 29.34mg/g without sink.Taiwanzi was the lowest as 4.46mg/g.(4)The content of flavonoids was significantly different among different varieties,the content of flavonoids containing sink was slightly higher than that withoutsink,the content of flavonoids of Taihezhu with sink was the highest as 0.96mg/g,the content of flavonoids of Pingyao containing sink was the lowest as 0.31mg/g,the content of flavonoids without sink had no obvious difference.(5)The total phenol content of yam containing sink was obviously greater than without sink.The total phenolic contentwith skin of Taihezhu is highest at 184.89mg/g,and the total phenolic content of the other nine varities is low with no significant difference.There is no significant difference in the total phenol content of different varieties without sink.(6)The content of allantoin in dioscoreae with skin is higher than that without skin,the difference in allantoin content between rhizomes of various varieties is not particularly large,but the content of allantoin in the skin of different varieties of dioscoreae still has a large gap,Dahechangyu has the highest skin allantoin content of 4.54mg/g,and Taiwanzi has the lowest skin allantoin content of 0.82mg/g.(7)There is no significant difference in total amino acid content among different dioscoreae varieties.Guannan has the highest total amino acid content of 10.59μmol/g and Pingyao has the lowest total amino acid content of 7.14μmol/g.Soluble sugar,starch,protein,etc.are mainly present in yam meat,and total phenols,flavonoids,etc.are very abundant in yam skin,so the role of yam skin should also be fully considered in the comprehensive development and utilization of yam.