Genetic analysis and QTL mapping of yield and fruit traits in bitter gourd (Momordica charantia L.)

Abstract

Bitter gourd (Momordica charantia L.) is an economically important vegetable crop grown in tropical parts of the world. In this study, a high-density linkage map of M. charantia was constructed through genotyping-by-sequencing (GBS) technology using F2:3 mapping population generated from the cross DBGy-201 × Pusa Do Mausami. About 2013 high-quality SNPs were assigned on a total of 20 linkage groups (LGs) spanning over 2329.2 CM with an average genetic distance of 1.16 CM. QTL analysis was performed for six major yield-contributing traits such as fruit length, fruit diameter, fruit weight, fruit flesh thickness, number of fruits per plant and yield per plant. These six quantitative traits were mapped with 19 QTLs (9 QTLs with LOD > 3) using composite interval mapping (CIM). Among 19 QTLs, 12 QTLs derived from ‘Pusa Do Mausami’ revealed a negative additive effect when its allele increased trait score whereas 7 QTLs derived from ‘DBGy-201’ revealed a positive additive effect when its allele trait score increased. The phenotypic variation (R2%) elucidated by these QTLs ranged from 0.09% (fruit flesh thickness) on LG 14 to 32.65% (fruit diameter) on LG 16 and a total of six major QTLs detected. Most QTLs detected in the present study were located relatively very close, maybe due to the high correlation among the traits. This information will serve as a significant basis for marker-assisted selection and molecular breeding in bitter gourd crop improvement.

Quantitative Trait Loci Mapping for Earliness, Fruit, and Seed Related Traits Using High Density Genotyping-by-Sequencing-Based Genetic Map in Bitter Gourd (Momordica charantia L.)

“…While genetic and QTL studies have been widely reported for some cucurbit, crops such as cucumber ( Wei et al, 2016 ; Win et al, 2017 ), bottle gourd ( Wu et al, 2017 ), pumpkin ( Zhang et al, 2015 ), watermelon ( Guo et al, 2015 ; Zhang et al, 2016 ; Gao et al, 2018 ), and melon ( Chang et al, 2017 ; Daley et al, 2017 ; Sheng et al, 2017 ), such studies for bitter gourd, a non-model plant, were very limited. To date, there have been a few reports on the identification of QTLs for horticulture traits in bitter gourd ( Kole et al, 2012 ; Wang and Xiang, 2013 ; Cui et al, 2018 ; Rao et al, 2018 , 2021 ). In the present study, we identified a total of 50 putative QTLs located on 10 chromosomes using the F 4 population from Punjab-14 and PAUBG-6.…”

“…Each horticulture trait was associated with an average of 5.5 QTLs. Recently, an average of 3 QTLs for six traits (fruit length, fruit diameter, fruit weight, fruit flesh thickness, number of fruits per plant, and yield per plant) in bitter gourd were reported by Rao et al (2021) . In cucurbits, an average of 4–6 QTLs for quantitative traits has been identified in many reports.…”

“…Apart from earliness, yield is another very important trait in bitter gourd which is complex in nature and is influenced greatly by flowering and fruit traits, such as number of staminate and pistillate flowers, number of fruits plant, length, diameter, and weight of fruits, plant vigor, and length of the vine of a particular genotype ( Iqbal et al, 2016 ; Singh et al, 2017 ). A few quantitative trait loci (QTLs) have been reported in bitter gourd relevant to yield component traits (fruit weight, length, and diameter) and earliness ( Kole et al, 2012 ; Wang and Xiang, 2013 ; Cui et al, 2018 ; Rao et al, 2018 , 2021 ).…”

Genome-Wide Association Studies Reveal Candidate Genes Related to Stem Diameter in Cucumber (Cucumis sativus L.)

“…Qi [ 7 ] constructed a four-generation population using muskmelon and cantaloupe as parents, and clarified that the melon stem diameter was inherited by two pairs of additive-dominant-epistatic major genes and additive-dominant polygenic genes. Rao [ 8 ] conducted a genetic analysis of the stem diameter of bitter gourd, and found that the inheritance of stem diameter conformed to the additive-dominant-epistatic polygenic genetic model. Lin [ 9 ] constructed a linkage group of chieh-qua, and detected one QTL of the chieh-qua stem diameter on LG2, with the phenotypic variation rate of 10.3%.…”

Unravelling the genetic architecture of grain quality traits under optimum and low-nitrogen stress conditions using tropical maize (Zea mays L.) germplasm

“…The most robust markers can then be employed for marker-assisted selection (MAS). However, the accuracy with which genetic maps are constructed is dependent on the mapping population since doubled haploid (DH) lines, near-isogenic lines (NILs), recombinant inbred lines (RILs), and backcross lines are extremely effective yet to date labour-intensive and time-consuming to generate (Rao et al 2021). GS has been highlighted as a powerful option for selecting polygenic traits that are di cult to select through MAS.…”