<div>Background: Blackgram [Vigna mungo (L.) Hepper] is an important food legume crop of India. Mungbean yellow mosaic virus (MYMV) disease is the major problem in blackgram. The disease can reduce seed yield upto 100% or even kill a plant infected at an early vegetative stage. The most effective way to prevent the occurrence of this disease is to develop genetically resistant cultivars of blackgram. However, a major difficulty in breeding MYMV disease resistant in blackgram is field screening for the virus disease.&nbsp;Hence identification of QTL followed by Marker-assisted selection (MAS) is highly useful for genetic improvement of crops. With this background, a study was made for identification as well as validation of quantitative trait loci (QTL) for MYMV disease resistance in blackgram. 
 
Methods: A total of 112 F2:3 lines were evaluated for MYMV disease resistance along with parents viz., MDU 1 (MYMV disease susceptible) and Mash 1008 (MYMV disease resistant) at the National Pulses Research Centre, Tamil Nadu Agricultural University, Vamban, Tamil Nadu during July-September 2018 under Augmented Design in the field. Each line was sown in one row of 3 m in length with a spacing of 30 cm as between row and 10 cm as within row. Susceptible genotypes CO 5 and MDU 1 were sown as disease spreader rows after every eight rows and also around the plots. The MYMV disease score was recorded on 60 DAS, by using phenotype rating scale from 1 (resistant) to 9 (highly susceptible), as suggested by Singh et al. (1995). The mean of each progeny was calculated and used as phenotypic data. A total of 525 SSR primers were used to test polymorphism between parents MDU 1 and Mash 1008. Genotyping was carried out for 112 F2:3 RILs of the cross MDU 1 x Mash 1008 with 35 polymorphic SSR markers. Linkage and QTL analyses were performed using QTL IciMapping (version 4.1.0.0) (Wang et al. 2016) and QGene 4.4.0 (Joehanes and Nelson 2008) respectively. Two mapping populations MDU 1 x Mash 114 and CO 5 x VBN 6 in F2:3 and F2 generations respectively were used in this study to validate the identified QTL regions. 
 
Result: QTL study indicated the presence of two major QTLs for MYMV disease score in LG 2 and LG 10 at 60 DAS with 20.90 and 24.90% of phenotypic variation respectively. Validation of these QTLs in two other mapping population indicated that QTL on LG 10 was validated with high phenotypic variation of 45.40-46.00%. Hence it may conclude that qmymv10_60 may be utilized for MAS/MABC with assured improvement on MYMV disease resistance in blackgram.</div>

<div>Identification and Validation of Quantitative Trait Loci of Mungbean Yellow Mosaic Virus Disease Resistance in Blackgram [Vigna mungo (L). Hepper]</div>

Background: Blackgram is one of the most important pulse crops. The post-harvest loss in blackgram is due to Callosobruchus maculatus where, the loss can go upto 100 per cent through secondary infestation. Development of cultivar with bruchid resistance can be cost-effective, durable and eco-friendly approach. The present study was conducted to identify markers linked to bruchid resistance in blackgram using the mapping population (RILs) developed from the cross between VBN(Bg) 5 (bruchid susceptible) and Vigna mungo var. silvestris 22/10 (bruchid resistant). 
 
Methods: A total of 191 RILs were subjected to bruchid screening and the traits viz., days to first adult emergence, mean developmental period, seed damage percent and growth index was observed. To analyse polymorphism between the parents, 343 SSR markers were screened and only 49 (14.29%) SSR markers showed polymorphism between the parents. Bulk segregant analysis (BSA) was done using resistant bulk and susceptible bulk along with parents using polymorphic markers. A total of eight SSR markers were identified as polymorphic in BSA. QTLs were mapped for seed damage per cent and growth index. The flanking markers for the QTLs identified for seed damage per cent and growth index was CEDG088 and CEDG118. Seed damage percent and growth index shared same position. The above markers were validated using four each of resistant and susceptible genotypes of blackgram. 
 
Result: The marker CEDG118 clearly distinguished the resistant and susceptible genotypes. The closely linked SSR marker CEDG118 could be used to screen the germplasm and segregating materials in order to identify bruchid resistant genotypes in blackgram.

Mapping of Quantitative Trait Loci for Bruchid Resistance in Blackgram [Vigna mungo (L.) Hepper]

Background: The YMD is one of the serious viral diseases in blackgram and is being transmitted by whitefly (Bemisia tabaci). The development of YMV resistant blackgram varieties is one of the important aspects for sustainable blackgram production. Marker assisted selection and genetic transformation could be utilized in developing YMV resistant blackgram genotypes. 
 
Methods: We attempted to map the QTLs governing YMV resistance in blackgram employing parents i.e., PBG32 (susceptible) and PU31 (resistant). Parental polymorphic studies were conducted using 147 SSR markers and genotyping and phenotyping data were used for QTL mapping. The markers, CEDG097 and CEDG172 that flanked to qYMV1 QTL were validated in 25 blackgram genotypes. 
 
Result: SSR markers showed 16% polymorphism between the parents. By using F2 genotypic data, genetic linkage map was constructed and total genetic map length observed was 335.47 cm. Single QTL (qYMV1) for YMV tolerance was detected and located between markers CEDG097 and CEDG172 with LOD score value of 2.76. The PVE by qYMV1 is 13.10% and the QTL is tightly linked (0 cM) to the left flanking marker CEDG97, which denotes a major QTL. Genotyping of the 25 known blackgram genotypes employing CEDG097 and CEDG172 markers, CEDG097 showed 91% linkage in known resistant and susceptible varieties to the YMV disease reaction and CEDG172 exhibited 74% linkage in known varieties to the YMV disease reaction. The resistance alleles (PU31 allele) of both markers i.e. CEDG097 and CEDG172 were recorded in VBN7, LBG922, LBG933 and TBG130-1 hence, these genotypes can be considered as potent YMV resistant varieties and also can be used as donor parents in resistance breeding programmes.

Quantitative Trait Loci (QTL) Detection and Validation of Linked Markers Associated with Yellow Mosaic Virus Resistance in Urdbean [Vigna mungo (L.) Hepper] in Andhra Pradesh

Background: Maize has wider adaptability and high yielding ability among the cereals. North-East India is a hotspot of the biodiversity of maize. Lots of local germplasms are distributed throughout various eco-geographic situations of hills and the plains of the entire region. Characterization of local germplasm of maize helps to identify genotypes with different features and also depicts a picture on genetic variability in the genetic resources studied. 
&nbsp; 
Methods: The present investigation comprised of a set of thirty five local germplasm along with five check hybrids in the crop was raised in augmented randomized block design duing rabi 2019 at Assam Agricultural University, Jorhat. Observation was recorded for twenty three quantitative characters. Analysis of variance and estimation of genetic parameter were done by using R software. 
&nbsp; 
Result: The present study revealed that the genotypes differed significantly among themselves for all the characters except ear leaf width and leaf width. Moderate to high estimates of GCV and PCV were recorded for all the traits except days to 75% dry husk, days to maturity and moisture content. Moderate to high estimates of heritability and genetic advance percent of mean were observed for all the traits. Grain yield per plant exhibited positive and highly significant correlation with traits namely ear length, ear diameter, kernel rows per ear, kernels per row, kernel length, kernel width and 100 kernel weights. PCA generated four principal components with an eigen value of more than 1.0 accounting for 67.74% of the overall variation present in maize germplasm. 
&nbsp;

Study on Genetic Variation, Trait Association and PCA of Different Quantitative Traits in Local Maize Germplasm

<div>Background: Soybean is an important oil and cash crop, soybean protein is the main source of protein for human consumption. Soybean oil is also major edible oil that is rich in unsaturated fatty acids and is more conducive to human long-term consumption than animal oil. An important research direction of current soybean breeding is improvement of the protein and fat content using marker assisted selection and many reports of associated quantitative trait locus (QTL) mapping have been documented. Until to now, a total of 241 QTLs associated with protein content and 315 related to fat content have been collected on the SoyBase website. 
 
Methods: In this study, 236 F2 generation plants and a derivative group were constructed by using Jiyu50 and Jinong18, obtained from Jilin Province. Combining three years of phenotypic and molecular detection data, using the ICIM method, one-dimensional scanning detected 24 QTLs related to protein and fat content, two-dimensional ICIM analysis of F2:3 families detected 7 pairs of epistatic QTLs associated with fat content. 
 
Result: Based on a mixed model for major genes and polygenes, the C model was determined the optimal genetic model for protein and fat content, with genetic rates of multiple genes of 71.15% and 79.15%, respectively. In the detection of high-oil molecular markers, the detection coincidence degree was Sat_238 &gt; Satt 100&gt; Satt 150 &gt; Satt 636&gt; Sat_287 = Sat_342, while this was Satt150 = Sat_342&gt; Satt100 &gt; Satt 636&gt; Sat_287&gt; Sat_238 for high-protein markers. The QTL localization results showed that 9 microeffect QTLs related to protein content and 7 microeffect QTLs related to fat content were detected. Isolation analysis results were generally similar to those of QTL mapping. One stable QTL associated with protein content and two stable QTLs associated with fat content were identified as being of some application value in soybean molecular marker-assisted breeding.</div>

Genetic Analysis and Quantitative Trait Locus Mapping using the Major Gene Plus Polygene Model for Soybean [Glycine max (L.) Merr.] Main Quality Trait

One hundred rabi sorghum germplasm lines of diverse origin were used to estimate genetic variability parameters such as heritability, genetic advance and correlation for 15 quantitative traits. The study was conducted under rainfed conditions during rabi season. High phenotypic coefficient of variation was observed for grain yield, panicle weight, panicle length, number of primaries and dead heart percentage. High heritability coupled with high genetic advance were observed for the characters days to flowering, dead heart percentage, panicle weight panicle length, number of primaries per panicle, test weight and grain yield per plant indicating that additive gene effects were operating for these traits and selection for superior genotype was possible to bring genetic improvement in desired direction. Grain yield had positive and highly significant association with plant height, panicle weight, number of primaries, panicle weight and test weight, whereas negative and highly significant correlation with seed fat content and protein content. 

Association studies between quantitative and qualitative traits in rabi sorghum

The present investigation was carried out to study stability performance over twelve environments for yield and yield contributing characters in twenty two genetically diverse genotypes of soybean using a randomized complete block design. The partitioning of (environment + genotype x environment) mean squares showed that environments (linear) differed significantly and were quite diverse with regards to their effects on the performance of genotypes for yield and its components. Stable genotypes were identified for wider and specific environments with high per se performance (over general mean) for majority of yield component traits. The investigation revealed that the genotypes ABL 55, ABL 20, ABL 62 and ABL 45 were desirable and stable across the environments for different yield contributing traits. Other genotypes ABL 43 and ABL 17 were found to be suitable for favourable situations, while genotypes ABL19 were adapted to poor environments for yield and majority of yield contributing traits.

Stability analysis for various quantitative traits in&nbsp;soybean [Glycine max (L.) merrill]

<div>Background: The narrow genetic base and environmental stresses are behind the low rate of faba bean yield in the past two decades. Drought stress is one of the most destructive abiotic stresses. Using induced mutagenesis on locally adapted landrace cultivar is proposed to cope with this problem.&nbsp; 
 
Methods: This study was conducted on faba bean landrace cultivar of Saudi Arabia, namely Hassawi 2, treated by 25 and 50 Gray gamma radiation. The genetic diversity assessment of M2 mutant populations was based on seven quantitative traits and nine Amplified Fragment Length Polymorphism (AFLP) primer combinations. &nbsp; 
 
Result: A total of 3419 M2 seeds were planted, of which 2782 (81.4%) seeds germinated and 2658 plants survived. A 5 to a 10-fold range of quantitative traits studied among mutant plants compared to control plants showed high variability. The number of pods per plant and seeds per plant was a valid selection criterion for a high-yielding faba bean breeding program. Nine AFLP primer combinations generated 1079 polymorphic alleles from 88 samples that comprised mutant and control plants. Shannon index (I) and expected heterozygosity (He) were 0.337 and 0.206, respectively. The AFLP results validated high variability in M2 populations. These findings will assist faba bean breeders in developing high-yielding cultivars with drought stress tolerance.</div>

<div>High Quantitative Trait Variability in Faba Bean Mutagenized Population for High-yielding Breeding Program in Saudi Arabia</div>

<div>Background: Over many centuries, the conventional methods of poultry breeding is based on the phenotypic selection of the birds with superior trait in a particular population. Prolactin is a physiological candidate gene that has significant effects on production traits in poultry. The objective of this study was to investigate 24 bp insertion (I) polymorphism of prolactin gene and its association with quantitative traits in Tellicherry native chicken. 
 
Methods: A total of 200 blood samples were collected from the randomly selected birds of All India Co-ordinated Research Project (AICRP) on Poultry Breeding, Mannuthy. The isolated DNA samples were subjected to polymerase chain reaction (PCR) by using specific set of primers to amplify the 24 bp insertion polymorphism. PCR amplicons were sequenced to study the polymorphism at nucleotide level. 
 
Result: PCR amplification revealed the presence of a specific DNA fragment with 130/154 bp contained 24 bp insertion polymorphism. Based on the polymorphic patterns birds were designated with three genotypes as II, ID and DD. The frequency of I (0.6975) allele was found higher than D (0.3025) allele. Our experimental results revealed that 24bp insertion polymorphism of prolactin did not have a significant association with production traits viz, age at sexual maturity, egg weight and egg number in Tellicherry native chicken.</div>

Characterization of 24bp Insertion Polymorphism of Prolactin Gene and its Association with Quantitative Traits in Tellicherry Native Chicken Breed

<div>Background: Among all the pulses, chickpea is the most important rabi crop with high acceptability and wider use in India. More availability of quality seed of improved varieties being made available to the famers is one of the most important factors contributing to better harvest of chickpea in recent years. Therefore, there is urgent need for developing high yielding varieties of chickpea employing sound and effective breeding strategies. The study of variability, correlation and path coefficient analysis for seed yield with other yield contributing characters is of immense importance to get information regarding exercising selections for genetic improvement in chickpea. 
 
Methods: A total of 40 genotypes of chickpea were undertaken for present study and these genotypes evaluated in randomized block design (RBD) with three replications at Rajasthan Agricultural Research Institute (SKNAU), Jaipur Rajasthan, India under late sown conditions during rabi 2019-20. The experimental unit was four row plots of 4 m long and spacing between row to row was kept to 30 cm and plant to plant was 10 cm. The genetic parameters viz., mean GCV, PCV, broad sense heritability, genetic advance (GA), correlation coefficient and path analysis were estimated. 
 
Result: Genotypes revealed significant wide genetic variation for almost all the quantitative traits. Number of pods plant-1 exhibited highest PCV and GCV. The highest broad sense heritability (h2b) was recorded for days to maturity followed by days to 50% flowering and 100-seed weight. The 100-seed weight, number of pods plant-1, number of seeds pod-1 and primary branches plant-1 had positive genotypic correlation with grain yield. Path coefficient analysis depicted that among the 9 causal (independent) traits; number of seeds pod-1, number of pods plant-1, number of primary branches plant-1, plant height from ground to first pod (cm) and days to 50% flowering had positive and directly influence on grain yield. Therefore these traits can be taken into consideration while exercising selection for grain yield in chickpea.</div>

<div>Variability and Character Association for Yield and Quantitative Traits under Late Sown Conditions in Chickpea (Cicer arietinum L.)</div>