Genetic Variation And Developmental Dynamics Of Chemical Constituents In Bitter Gourd Fruits

Bitter gourd(Momordica charantia L.)is one kind of popular vegetable crop with medicinal function.Its fruits contain a variety of nutrients,as well as many physiologically active substances.The active ingredients and their effects of Momordica charantia have become a hot research in biology,nutrition and medical fields.The content of seven kinds of biochemical components(Polysaccharides,vitamin C,saponins,chlorophyll,anthocyanins,soluble proteins and flavonoids)of fruit and five kinds of mineral elements(K,Mg,Ca,Fe andZn)in 39 bitter gourd genotypes were determinated,and their genetic variation on levels was analysised in this study.Moreover,four genotypes were chosen typically as the materials to study the dynamic variation of chemical ingredients on fruit development procedure.The study is aimed at revealling the levels variance of chemical components among the germplasm of Momordica charantia and their characteristics of accumulation in fruit development in the field.It will be helpful to the study on chemical ingredients in bitter gourd,as well as to provide the technical basis for bitter gourd germplasm screening,product quality breeding,acquisition and development of health care products.The main results are as follows:1.All of the fruit’s main morphological characters existed variance among bitter gourd genotypes.Coefficient of variation can be listed from big to small as follw:melon shape 52.43%,weight of single fruit 50.57%,commodity melon cooked sex48.41%,melon tumor size 44.70%,melon leng size 43.31%,melon type index39.96%,melon color 34.82%,melon tumor shape,33.68%,melons length 31.82%,fruit flesh thickness 27.79%,melon diameter 24.06%,melon tumor density 21.62%.2.The content of 12 kinds of organic chemical constituents existed significant differences among accessions tested.The variation coefficient in 7 chemical components was 25.54%~80.62%,the order is polysaccharide,vitamin C,saponin,chlorophyll,anthocyanin,soluble protein,flavone,and the average of variation coefficient was 42.23%.The variation coefficient of 5 mineral elements was12.21%~55.99 %,followed by: Fe > Mg > Ca > Zn > K,the average coefficient of variation was 29.92%.3.Correlation analysis showed that the positive correlation or negative onebetween each two factors was revealled,respectivelly.The results were as follows,the combination of highly significant positive correlation are vitamin C & Fe、K、Zn;saponins & Zn,protein & soluble flavonoids;flavonoids & Ca;chlorophyll &anthocyanin;Fe & Zn;Zn & Ca.There was a very significant positive correlation between K & Mg;Ca & vitamin C、saponin;soluble protein& polysaccharide;K &flavonoids、polysaccharide、anthocyanin;anthocyanins & Ca.Saponin & chlorophyll;polysaccharide & Fe、Zn;Zn & K have highly significant negative correlation.It had a significant negative Correlation between saponins &lavonoids;soluble protein & Zn;chlorophyll & Ca.4.There is a certain different on 12 chemical levels among different fruit pericarp color and fruit shape in bitter gourd.The green strip of balsam pear content the highest chemical composition,and the content of mineral elements and white gourd cone are higher.5.The results of cultivar cluster analysis based on 12 kinds of chemical components showed that accessions could be divided into 5 groups when the euclidean distance is 2.38,and 2,4,7,13,16,24,28 for each group,and the others in one group.Furthermore,the latter one could be divided into two subgroups,1 and 9 in one subgroup,and the rest in another subgroup.6.The trend of 12 chemicals in dynamic changes in different types of bitter gourd fruits is comprehencive.With the development of fruit,the content of chlorophyll and anthocyanin in the flesh of different types of bitter gourd decreased,and the peak value was the 7th day after pollination;polysaccharide content showed an upward trend,the peak appeared in the pollination after the first 25 days;Ca content increased first and then decreased,and the content of other chemical substances in the flesh of the unit was different due to the different trend of different types of varieties,the peak time was different and the peak value was different too.In summary,the morphological characters of fruits,the chemical composition of fruits and the dynamic changes of various chemical composition studies showed that bitter gourd varieties had abundant genetic diversity and germplasm specificity,this has laid a theoretical foundation and technical guidance for the breeding of new varieties of bitter gourd and the excavation of functional gourd resources.