Preliminary Study on the Quality Difference of Local Broad-shoulder Bitter Gourd Landraces in Foshan

[Objectives]The study aims to provide important reference for the breeding and research of new varieties of functional broad-shoulder bitter gourd.[Methods]8 pure varieties of local broad-shoulder bitter gourd landraces in Foshan were used as experimental materials,in which polysaccharide,cellulose and vitamin C content were measured.[Results]Among the 8 varieties of local self-selected broad-shoulder bitter gourd in Foshan,the polysaccharide content of Foxuan 6 was the highest,up to 113.78 mg/100 (g·FW),which was significantly higher than that of the other 7 varieties.The polysaccharide content of Foxuan 2 was the lowest.The cellulose content of Foxuan 8 was the highest,reaching 24.50 mg/100 (g·FW),which was significantly higher than that of the other 7 varieties.The cellulose content of Foxuan 4 was the lowest.The vitamin C content of Foxuan 5 was the highest,reaching 74.24 mg/100 (g·FW),which was significantly higher than that of the other 7 varieties.The vitamin C content of Foxuan 4 was the lowest,only 7.05 mg/100 (g·FW).In a word,there were big differences between the 8 varieties of broad-shoulder bitter gourd in terms of polysaccharide,cellulose and vitamin C content.[Conclusions]It is possible to make full use of their own quality differences and develop new varieties of functional broad-shoulder bitter gourd by means of cross combination.

A 1-bp deletion in the MC04g1399 is highly associated with failure to produce fruit wart in bitter gourd

Fruit wart is an important appearance trait influencing consumer preferences of bitter gourd(Momordica charantia L.).The molecular genetic mechanisms underlying fruit wart formation in bitter gourd are largely unknown.In this study,genetic analysis based on four generations showed that fruit wart formation in bitter gourd was controlled by a single dominant locus named as Fwa.The Fwa locus was initially mapped into a 4.82 Mb region on pseudochromosome 4 by BSA-seq analysis and subsequently narrowed down to a 286.30 kb region by linkage analysis.A large F2population consisting of 2360 individuals was used to screen recombinants,and the Fwa locus was finally fine mapped into a 22.70 kb region harboring four protein-coding genes through recombination analysis.MC04g1399,encoding an epidermal patterning factor 2-like protein,was proposed as the best candidate gene for Fwa via sequence variation and expression analysis.In addition,a 1-bp insertion and deletion(InDel)variation within MC04g1399 was converted to a cleaved amplified polymorphic sequence(CAPS)marker that could precisely distinguish between the warty and non-warty types with an accuracy rate of 100%among a wide panel of 126 bitter gourd germplasm resources.Our results not only provide a scientific basis for deciphering the molecular mechanisms underlying fruit wart formation but also provide a powerful tool for efficient genetic improvement of fruit wart via marker-assisted selection.

Genetic Analysis of the First Female Flower Node and the First Male Flower Node in Bitter Gourd

Exploring genetic mechanism of the first female flower node and the first male flower node in bitter gourd has practical significance for formulating breeding strategy. In this article, a cross was made between CN19-1 and Thai4-6, and the F2segregation population was also constructed through F1selfing. The genetic characteristics of the first female flower node and the first male flower node were analyzed by adopting the major gene plus polygene mixed genetic model. The data analysis results showed that the first female flower node and the first male flower node were continuous distribution in the F2segregation population. E-2 model was the most suitable model for the genetic analysis of the first female flower node and the first male flower node. The additive effect values of the 2 pairs of major genes controlling the first female flower node were 2.722 and 1.862 8 respectively, the dominant effect values were-2.721 6 and-0.171 8, respectively. The additive effect value of polygene was-0.839 2, and the dominant effect value of polygene was 2.225 4. The heritability of major genes and polygene were 83.73% and 1.54%, respectively. The additive effect values of the 2 pairs of major genes controlling the first male flower node were 17.746 9 and 3.972, respectively, the dominant effect values were 5.191 6 and-3.972, respectively. The additive effect value of polygene was-20.530 5, and the dominant effect value was-4.141 4. The heritability of major genes and polygene was 92.34% and 4.7%, respectively. This study could provide a theoretical basis for bitter gourd breeding.

Study on Genetic Diversity of Agronomic Traits and Genetic Relationships among Core Collections of Bitter Gourd

[Objective] This study aimed to investigate the genetic diversity of agronomic traits and genetic relationships among core collections of bitter gourd.[Method] Total 141 germplasms of bitter gourd were selected,and the genetic diversity of 13 agronomic traits was analyzed.In addition,total 46 core collections of bitter gourd were employed,and their genetic relationships were analyzed based on the phenotypic values and genotypic values of 5 agronomic traits,respectively.[Result] The genetic diversity analysis of agronomic traits showed that the genetic diversity indexes of the 4 qualitative traits of bitter gourd germplasms ranged from 0.46 to 1.34;the distribution of the 9 quantitative traits data was more dispersed with average coefficient of variation of 20.02%.The genetic relationship analysis showed that based on the phenotypic values and genotypic values of the 5 quantitative traits,the genetic distances among the 46 core collections of bitter gourd were different.Based on the genotypic values,the genetic distances among the 46 bitter gourd core collections ranged from 0.84 to 10.71.The 46 germplasms were divided into 17 groups with the rescaled distance of 8.5,which further classified the relationships among different germplasms.[Conclusion] This study will lay a solid foundation for the effective utilization of core collections and new variety breeding in bitter gourd.

Effects of Controlled Release Nitrogen Fertilizer on Seedling Growth and Nutrient Uptake of Bitter Gourd

Different application rates of controlled release nitrogen fertilizer （CRFN） were designed to evaluate their effects on the growth and root morphology of bitter gourd （Momordica charantia L.） seedlings, and thus determine the optimal nitrogen amount and suitable nitrogen content in substrate at seedling transplanting,, in com- parison with conventional fertilizer application. CRFN was applied at five levels, 0, 0.6, 1.2, 2.4 and 4.8 kg N/m3, and conventional fertilizer was applied at 0.6 kg N/m3 as control. Four replicates were included in each treatment. The results showed that 0.6-2.4 kg N/m3 CRFN provided sufficient N nutrient for bitter gourd, with higher shoot and root dry weights, root length and root surface area than control treat- ments. Correspondingly, the total inorganic nitrogen in substrate ranged from 99.3 to 162.5 mg/pot at seedling transplanting in these treatments. 1.2 kg N/m3 was proven to be the optimal CRFN rate. Compared with conventional nitrogen fertilizer applica- tion, 1.2 kg N/m3 CRFN in substrate increased the dry weight, nitrogen uptake and improved root morphology indices of seedlings, and more than 83.3 mg/pot inorgan- ic nitrogen could be carried with substrate at transplanting, revealing a potential to reduce N-deficient risk after rain and basal N input by continuous release of CRFN.

Identification of Genetic Purity of Bitter Gourd Hybrid by ISSR Markers

Objective] This study was conducted to verify the feasibiIity of ISSR marker for identifying genetic purity of bitter gourd hybrid, and thus to provide an effective method for seed purity test in production practices. [Method] The DNA fin-gerprints of a bitter gourd cuItivar Xiuyu 1 and its parents were analyzed using IS-SR marker with 91 primers. [Result] Two primers ISSR-845 and ISSR-891 which ampIified two DNA bands of 510 and 300 bp respectiveIy from F1 generation and its parents were screened out from 91 primers. ISSR-845 couId distinguish the male parent from F1 hybrid and the female parent, whiIe ISSR-891 couId distinguish the female parent inbred Iine from Xiuyu 1. Seed purity test with the specific markers gave the same resuIt with fiIed trials based on morphoIogical identification. [Conclu-sion] ISSR marker is an accurate, simpIe and effective method for seed purity test bitter gourd hybrid, and thus can be used in production practices.

Isolation and Identification of Fusarium Wilt Pathogens from Bitter Gourd in Hainan Province

In order to isolate and identify the pathogens causing Fusarium wilt in bitter gourd in Hainan Province, China, four bitter gourd plants exhibiting symptoms of Fusarium wilt were collected from Tunchang County, Hainan Province. Four pathogen strains （HNTC-01, HNTC-02, HNTC-03 and HNTC-04） were isolated from the four plants, and identified via morphological observation and molecular techniques. The results showed that HNTC--01, HNTC-03 and HNTC-04 were F. oxysporum, while HNTC-02 was F. graminearum. The tests on pathogenicity and host specificity showed that HNTC-01, HNTC-03 and HNTC-04 were F. oxysporum Schl. f. sp. momordicae. Phylogenetic analysis revealed that HNTC-01, HNTC-03, HNTC-04 were clustered together with 14 strains of F. oxysporum, and HNTC-02 was clustered together with six strains of F. graminearum. In addition, rDNA-ITS region can be used to distinguish different Fusarium species, but can not be used to distinguish different biotypes within a Fusarium species. This study could provide a scientific basis for the diagnosis and prevention of wilt in bitter gourd.

Occurrence and Control Technology of Bitter Gourd Fusarium Wilt

With the increase of growing area of bitter gourd, Fusarium wilt has become one of the most important diseases in bitter gourd production, seriously affecting the yield and quality of bitter gourd. The occurrence regularity of bitter gourd Fusarium wilt was expounded, and the research status of agricultural control, chemical control and biological control were summarized, so as to provide the reference for safe and efficient production of bitter gourd.

Effects of Cultivation Method on Seed Yield and Quality of Bitter Gourd

This experiment was carried out to study the possibility of producing germinating seeds of bitter gourd(Momordica charamtia L.)in the climatic conditions of Europe.Seeds of Indian cultivar‘Nana’were sown in the greenhouse and produced transplants were planted on the field.The plants were cultivated in the field in 2 ways:tied to the sticks or creeping on the ground.During the vegetation,the ripen fruits with seeds were collected 6 times,and after extracting,they were germinated in the laboratory following the routine ISTA rules.The best transplants of bitter gourd were received within one month from the seeds emerging 51.8%.The transplant of bitter gourd had average height of7 cm,3-4 leaves,out of which the biggest had the width of 5 cm.Such transplants would grow into fruiting plants.When growing bitter gourd for seeds,the earliest fruits were harvested from the plants tied to the sticks.Moreover,the best seeds were harvested from 2/3 of early fruits.For the purpose of seed production,it is recommended to keep only 3-4 fruits per plant and remove other fruits.The produced seeds germinated from 8%to 24%.If the plants were tied to the sticks,their fruits ripened earlier.The used production way and time of harvest of fruits had no effect on the seed germination.The cultivation methods of bitter gourd plants had no effect on the chemical components of fruits.

GC-MS Analysis of Liposoluble Components in Seeds of Bitter Gourd from Different Sources

[Objectives]This paper aimed to analyze the liposoluble components in seeds of different bitter gourd germplasms.[Methods]Taking 3 bitter gourd germplasms from different sources as materials,the composition and relative contents of liposoluble components in the seeds were analyzed using gas chromatography-mass spectrometry(GC-MS).[Results]A total of 22,18 and 18 compounds were detected from Papua,Y7 and Y108,respectively,accounting for 38.63%,90.20%and 92.53%of the total liposoluble components.Among them,eight liposoluble components were unique to Papua,and two liposoluble components were unique to Y108.The composition and relative contents of liposoluble components differ among different bitter gourd germplasms.The main chemical components wereγ-tocopherol,vitamin E,andβ-tocopherol.The content ofγ-tocopherol was high in the three germplasms,accounting for 8.885%,20.090%and 20.314%,respectively.[Conclusions]This study can lay the foundation for breeding functional bitter gourd varieties.

Identification and Evaluation of Resistance to Meloidogyne incognita in Bitter Gourd Germplasms

[ Objective] This study aimed to identify and evaluate the resistance of bitter gourd germplasms to Meloidogyne incognita. [ Method] A total of 71 bit-ter gourd germplasms were artificially inoculated with M. incognita at seedling stage to investigate the effects of M. incognita on resistance indexes of bitter gourd seedlings. Cluster analysis and subordinate function analysis were performed to identify and evaluate the resistance of experimental materials. [ Result] The infec-tion of M. incognita increased the variation coefficients of resistance indexes. The resistance to M. incognita varied significantly among different bitter gourd germ- plasms. Based on gall index, 71 bitter gourd germplasms were divided into five types by cluster analysis, including resistant materials, moderately resistant materi-als ,moderately susceptible materials, susceptible materials and highly susceptible materials. The subordinate function analysis showed that total subordinate func-tion values of Y107, Y109, Y108, Y51, Y105, Y81, Y89, Y140 and Y94 exceeded 1.95 , indicating high resistance to M. incognita. [ Conclusion] This study could provide resistant materials for breeding root-knot nematode resistant varieties of bitter gourd.

The Genetic Analysis of Internode Length in Bitter Gourd

Performing the genetic mechanism research of internode length in bitter gourd has important guiding significance for making breeding strategy. A cross was made between CN19-1 and Thai4-6, and an F2 segregation population was constructed. The genetic characteristic of the internode length was analyzed through employing the major gene plus polygene mixed genetic model. The results showed that the internode length was continuous distribution in the F2 population. The optimum model for internode length genetic analysis was B-1. The additive effect values of two pairs of major genes controlling the internode length were 3.206 3 and 2.638 3, respectively, which showed a positive effect. The dominant effect values were-3.434 6 and-1.459 6, respectively, which showed a negative effect. The dominant degree of major genes is-1.07 and-0.55, respectively, indicating that the first pair of major genes was over dominant and the second pair of major genes was incompletely dominant. The heritability of the major gene was 82.25%, indicating the genetic stability was high. This study could provide a theoretical reference for the breeding of bitter gourd.

Study on Cold Tolerance Identification Indices for Bitter Gourd Germplasms

The selection of cold tolerance identification indices for bitter gourd germplasms is an important basis for the breeding of cold-tolerant bitter gourd varieties. In this study, with six bitter gourd germplasms as experimental materials, the cold injury index of bitter gourd was analyzed under low temperature treatment, the changes in physiological indices were revealed, and the main agronomic traits were measured. The results showed that the cold injury index of bitter gourd was in very significant negative correlation with SOD activity, POD activity and PRO content, in significant negative correlation with CAT activity, in very significant negative correlation with flowering node and commodity rate, but in significant positive correlation with female flower ratio. It was found that that cold injury index, SOD activity, POD activity, CAT activity and PRO content could serve as the cold tolerance identification indices for bitter gourd at seedling stage, and flowering node and commodity rate could be used as the auxiliary indices for field cold tolerance identification.

Bitter gourd extract improves glucose homeostasis and lipid profile via enhancing insulin signaling in the liver and skeletal muscles of diabetic rats

Objective:To investigate the modulatory effects of bitter gourd extract on the insulin signaling pathway in the liver and skeletal muscle tissues of diabetic rats.Methods:The ethanolic extract of bitter gourd was prepared and its contents of total polyphenols and flavonoids were assayed.A neonatal streptozotocin-induced diabetic rat model was established and the diabetic rats were assigned into different groups and were treated with different doses of bitter gourd extract(100,200,400,or 600 mg/kg)or with glibenclamide(0.1 mg/kg)for 30 d.Fasting blood glucose,insulin,and lipid profile were evaluated and the insulin signaling pathway in the liver and skeletal muscle of rats was investigated.The correlations between homeostasis model assessment(HOMA)and the components of insulin signaling pathway were also evaluated.Results:Different doses of bitter gourd extract significantly ameliorated fasting blood glucose level and HOMA index for insulin resistance.Moreover,bitter gourd extract increased serum insulin and improved disrupted serum lipid profile.The levels of insulin receptor substrate-1(IRS-1),p-insulin receptorβ(p-IR-β),protein kinase C(PKC),GLUT2,and GLUT4 were improved by treatment with bitter gourd extract.The best results were obtained with 400 mg/kg dose of the extract,the effect of which was equivalent to that of glibenclamide.HOMA in the bitter gourd treated rats was negatively correlated with p-IR-β,IRS-1 and PKC in hepatic and skeletal muscle.HOMA was also negatively correlated with skeletal muscle GLUT4.Conclusions:Bitter gourd extract improves glucose homeostasis and lipid profile in diabetic rats via enhancement of insulin secretion and sensitivity.Therefore,bitter gourd can be used as a potential pharmacological agent for the treatment of type 2 diabetes mellitus.

Review of Research on Sex Differentiation in Bitter Gourd(Momordica charantia L.)

Bitter gourd,with its narrow genetic background and rich sexual type,is a preferred material to be used to study the gender differentiation of flower buds of monoecious plants.This article is a review of studies on the gender differentiation of flower buds of bitter gourd,from morphology to cytology,from classical genetics to molecular biology,and the mechanism by which it is regulated.The recent rapid development of whole genome sequencing and high throughput sequencing provides a novel approach to the study of the gender differentiation of flower buds of bitter gourd.The study of the gender differentiation of flower buds of bitter gourd can provide references for the regulation of gender differentiation and molecular breeding of bitter gourd.

Field Evaluation on Agronomic Characteristics of Newly Introduced Bitter Gourd(Momordica charantia L.)Accessions in Thua Thien Hue Province,Vietnam

The main objective of this study was to evaluate ability of growth and yield of introduced bitter gourd accessions in winter-spring 2016-2017 in Thua Thien Hue province.A total of seven accessions were used in this study.Of these,six accessions were provided by the World Vegetable Center(AVRDC),namely,AVRDC 1329,AVRDC 1330,AVRDC 1331,AVRDC 1333,AVRDC 1334,AVRDC 1335 and one Vietnam local accession(control)from Dien Hai commune,Phong Dien district,Thua Thien Hue province.The results showed that experiment accessions can grow under Thua Thien Hue conditions.AVRDC 1329,AVRDC 1330,and AVRDC 1335 were considered as displaying good growth and development ability.Of those,AVRDC 1330 was the most suitable to consumer as regards to appearance and bitter taste.AVRDC 1330,the control check and AVRDC 1331 had the high actual yield with 16.57,10.65 and 7.88 tons/ha,respectively,and these two introduced accessions can be used for breeding and cultivation under local condition.

Screening of Bitter Gourd Hybrid Combinations with High Yield and Disease Resistance

[Objectives]This study was conducted to breed and promote high-yield and disease-resistant varieties of bitter gourd.[Methods]The comparison experiments of six new hybrid combinations(Z1705,Z1706,Z1717,Z1721,Z1732,Z1745)were successively carried out at two experimental sites of Danzhou and Tunchang.[Results]Comparing the agronomic traits and disease resistance of various combinations,it was concluded that Z1717 and Z1721 have high yields,green and glossy fruit surface and good comprehensive disease resistance,so they can be popularized and planted.[Conclusions]This study is of great significance for improving the yield of bitter gourd and increasing economic benefits.

Genetic Analysis of Leaf Length and Leaf Width in Bitter Gourd

[Objectives]To explore the genetic mechanism that leaf length and leaf width in bitter gourd has realistic guiding significance for formulating breeding strategy.[Methods]In this paper,the cross was made between CN19-1 and Thai4-6 and an F2segregation population was constructed.The genetic characteristics of leaf length and leaf width were analyzed by employing the major gene plus polygene mixed genetic model.[Results]The data analysis results demonstrated that the leaf length and leaf width of the F_(2) segregation population showed continuous distribution.The optimum model for leaf length genetic analysis was A-1,the additive effect value of the major gene was 3.1766,the dominant effect value was-3.1766,and the heritability was 74.51%.The optimum model for leaf width genetic analysis was B-1.The additive effect values of 2 pairs of major genes controlling the leaf width were 3.1917 and 0.9623,respectively.The dominant effect values were-1.3135 and-0.3463,respectively.The additive×additive interaction effect was-0.3591,the additive×dominant interaction effect was-0.2570,the dominant×additive interaction effect was 1.9916,the dominant×dominant interaction effect was 1.9686.The heritability of major genes was 96.67%.[Conclusions]This study is expected to provide a theoretical basis for the breeding of bitter gourd.

Genetic Analysis of Weight per Fruit and Fruit Length in Bitter Gourd

[Objectives]The paper was to verify the genetic mechanism of weight per fruit and fruit length in bitter gourd and to provide guidance for formulating breeding strategy.[Methods]In this study,a cross was made between CN19-1 and Thai4-6,and a Fsegregation population was also constructed.The genetic characteristics of weight per fruit and fruit length were analyzed by employing major gene plus polygene mixed genetic model.[Results]The weight per fruit and fruit length showed continuous distribution in Fsegregation population.The optimal model for weight per fruit and fruit length was the same(A-1 model).The major gene additive effect value of weight per fruit was 46.1474,the dominant effect value was-46.1005,and the major gene heritability was 52.47%.The major gene additive effect value of fruit length was 2.456,the dominant effect value was-2.455,and the major gene heritability was 52.52%.The results showed that weight per fruit and fruit length were mainly controlled by a pair of major genes.[Conclusions]This study can provide a theoretical basis for bitter gourd breeding.

Genetic Analysis of Main Plant Type-related Traits in Bitter Gourd(Momordica charantia L.)

In this study,the cultivated bitter gourd inbred line‘Foli 112’and the wild bitter gourd accession THMC170 were used as female(P1)and male(P2)parent,respectively,to obtain 4 generations(P1,P2,F1 and F2)through self-crossing and hybridization.The mixed major gene plus polygene inheritance model of plant quantitative trait was used to perform genetic analysis for 5 plant type-related traits including the number of internode,leaf length,leaf width,stem width and internode length in bitter gourd.Results showed that the inheritance of internode number,leaf length and leaf width was in accordance with E-6 model which involved two pairs of equi-dominant major genes with additive-dominant polygene model;the stem width was controlled by additive-dominance-epistasis polygene inheritance model(C-0 model);the inheritance of internode length involved 2 pairs of equi-additive major genes with additive-dominant polygene model(E-4 model).Meanwhile,the heritability(h2)of stem width and internode number was 20.08%and 39.28%,respectively,indicating that they were vulnerable to environment impacts;leaf length,leaf width and internode length had a higher heritability of 51.50%,52.16%and 64.36%,respectively;the inheritance of leaf length was mainly controlled by major gene(the heritability of major gene was 40.75%),indicating that early-generation selection was better for leaf length,while the inheritance of leaf width and internode length was mainly controlled by mutiple minor genes,indicating that it was better to select these two parameters for late generation.