<div>Background: Pedigree method of breeding in predominantly self-pollinated crop like dolichos bean enable exploiting only fixable genetic effects as a result of rapid increase in homozygosis. One or a few cycles of inter-mating in F2 generation help create populations with high frequency of desired recombinants which otherwise cannot be realized in later generations. The objective of the present investigation was to assess the impact of inter se mating in F2 population on nine quantitative traits&rsquo; (QTs) mean and variability parameters. 
 
Methods: Randomly selected 20 pairs of a single cross-derived F2 plants with flowering synchrony were inter se mated. Progenies derived from 20 paired crosses (designated as BIP F3 progenies) and those (F3) derived from their 40 F2 parents were evaluated for 9 QTs. Statistics such as mean, absolute range (AR) and standardized range (SR), variance (&sigma;2), additive genetic variance (&sigma;2A) and narrow-sense heritability (NS-h2) were estimated. BIP F3 progenies were compared with those of F3 progenies for QTs mean, AR/SR, &sigma;2, &sigma;2A and NS-h2. Significance of differences between BIP F3 progenies and F3 progenies for mean and &sigma;2 were examined using two-sample t test and Levene&rsquo;s tests, respectively.&nbsp; 
 
Result: The random mating in F2 population was effective in increasing the means, variances, &sigma;2A and NS-h2 of racemes plant-1, fresh pods node-1, fresh pods plant-1 and fresh pod yield plant-1 in dolichos bean. Considering that random mating followed by selfing is a method of genetic improvement for future breeding rather than for immediate use, our results suggest long-term genetic gain and better prospects of deriving superior pure-lines with desired traits/combination of traits from inter-mated population in dolichos bean.</div>

<div>Effect of F2 Inter se Mating on Quantitative Traits Mean, Range, Variance and Heritability in Dolichos Bean (Lablab purpureus L. Sweet var. Lignosus)</div>

Background: Blackgram is an important pulse crop grown in India. The creation of new variability through hybridization or mutation breeding will produce novel segregants for important yield attributing traits. The selection from the population will be effective if the traits have good genetic variability estimates. 
 
Methods: The present investigation was conducted on analysing genetic variability parameters in F2 populations of the blackgram crosses CO 5 &times; VBN 9 and CO 6 &times; VBN 11 which were evaluated during rabi, 2022. 
 
Results: Based on the coefficient of variations, it was found that sufficient amount of genetic variability and high to moderate heritability with high genetic advance were present in the populations for the traits viz., plant height, number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant and seed yield per plant indicates the presence of additive gene action which can be improved by simple selection in the earlier generations. The positive skewness was observed for the traits viz., number of branches per plant, number of pods per cluster, number of pods per plant, hundred seed weight and seed yield per plant in F2 population of CO 5 &times; VBN 9 and number of clusters per plant, number of pods per cluster, number of pods per plant and seed yield per plant in the F2 population of CO 6 &times; VBN 11. The above traits could be improved by intensive selection for rapid improvement. The leptokurtic nature of the distribution for the trait hundred seed weight in CO 5 &times; VBN 9 population and the traits viz., number of clusters per plant, number of pods per plant, pod length, number of seeds per pod and seed yield per plant in CO 6 &times; VBN 11 population indicates these traits are controlled by few minor genes. Hence, the good segregants could be selected from these two populations for yield improvement.

Genetic Analysis of F2 Populations for Quantitative Traits in Blackgram [Vigna mungo (L.) Hepper]

<div>Background: Among several reasons for low productivity in mungbean, various biotic and abiotic factors play a major role. Although intensive research work has been done on genetic architecture of yield and yield attributes of mungbean but limited work was done on yield attributes along with water use efficiency (WUE) and heat stress tolerance related traits. The present study is aimed to identify the genetic potential of mungbean genotypes with high yield and drought and heat stress tolerance. 
 
Methods: The F2 seed was harvested from selfed F1 population during 2017-18 from three superior crosses viz., ML 267&times;LGG 528, MGG 390&times;LM 95 and LM 95&times;EC 362096. These crosses were selected based on their per se performance of yield, yield attributes and WUE related traits. Genetic analysis was carried out in F2 populations of three crosses for fourteen quantitative characters to identify the number of transgressive segregants in desirable direction. 
 
Result: A good number of transgressive segregants in desirable direction were observed for plant height, number of pods per cluster, harvest index, SLA, SLW and relative injury in the cross ML 267&times;LGG 528: for plant height, number of branches per plant, SCMR, SLA, SLW and relative injury in the cross MGG 390&times;LM 95 and for plant height, number of pods per cluster, number of pods per plant SCMR, SLA, SLW, relative injury and seed yield in the cross LM 95&times;EC 362096.</div>

Transgressive Segregants in F2 Populations of Three Superior Crosses viz., ML 267&times;LGG 528, MGG 390&times;LM 95, LM 95&times;EC 362096 in Mungbean

<div>Background: Combining ability is a measure that enables breeders to select better parents and outstanding hybrids. General combining ability and specific combining ability is used to determine best performing parents and vigorous hybrids respectively and provides an opportunity to understand the nature of gene action involved in inheritance of each character. 
 
Methods: A combining ability analysis was carried out with six mungbean varieties and their 15 F2 crosses derived from half diallel fashion. Data was recorded for 10 characters and were subjected to statistical analysis using method-II and model-1 of Griffing&rsquo;s approach. 
 
Result: There was importance of both additive and non-additive gene action in inheritance of all the characters as apprehended from significant values in mean sum of square due to GCA and SCA. Studies on components of variance due to GCA and SCA indicated there was preponderance of additive gene action for days to 50% flowering, days to maturity and pod length whereas non-additive gene action was expressed for other characters. Four parents viz., Kamdev, Pant Mung-8, MGG-385 and OBGG-52 were considered as best general combiners on the basis of significant GCA effects for a number of yield and its related traits. Based on SCA effects and per se performance, the crosses IPM-02-14/OBGG-58, OBGG-52/OBGG-58 and MGG-385/OBGG-52 displayed significant SCA in desirable direction along with high mean for many of the yield attributing characters. Highest significant SCA for seed yield was observed by the cross Kamdev/IPM-02-14. These selected parents and crosses can be used for further breeding programmes for crop improvement in mungbean.</div>

Combining Ability Studies for Seed Yield and its Quantitative Traits in F2 Crosses of Mungbean [Vigna radiata (Wilczek)]

Background: Hybrid breeding in Okra [Abelmoschus esculentus (L.) Moench] is important to improve productivity of this crop. Given that a breeder&rsquo;s primary goal is production, it&rsquo;s critical to understand the connections between the traits that have a direct and indirect impact on yield. 
 
Methods: 45 hybrids generated by crossing 10 diverse parents in structured mating design were evaluated to estimate the magnitude of their genetic variability and heritability in F2s. Mean performance across three replications were calculated for 21 traits and is assessed for their effect on yield. The recorded data were statistically analyzed at 5% level of significance by multivariate analysis using principal component and hierarchical cluster. 
 
Result: For all of the analyzed traits, the analysis of variance revealed a highly significant difference between population. A greater difference between PCV and GCV estimates for days to anthesis, days to 50% flowering and days to first picking indicates a greater degree of environmental control for these traits. Traits such as days to anthesis, days to 50% flowering and days to first picking shows low to moderate heritability. These findings show that there is enough genetic diversity in these parameters to support selection of better accessions. Using cluster analysis and principal component analysis (PCA), crosses were divided into groups based on their performance and the identification of the most discriminating attribute that accounted for the greatest variability. It revealed that yield per plant is highly associated with days to first picking, days to 50% flowering, days to anthesis, plant height and shoot length. Further, principal component shows 1000-seed weight and germination percentage followed by days to 50% flowering as the most discriminating trait. Hence, selection for any trait would favor future hybrids breeding programmes.&nbsp;

&nbsp;

Study of Genotypic and Phenotypic Variation in F2 Segregating Generation of Okra [Abelmoschus esculentus (L.) Moench]&nbsp;

Fifty nine land races from 42 countries and 62 elite breeding lines developed at Indian Institute of Pulses Research, Kanpur, were screened against Fusarium wilt (race 2) under sick-field. Among land races the per cent wilted plants at seedling and reproductive stages ranged between 0 to 31.5% and 3.1 to 100%, respectively. Eightland races (ILC8632, ILC8666 ILC10729, ILC0, ILC1313, ILC211, ILC68 andILC0) were found highly resistant.The per centage of early wilting among elite breeding lines consisting of &lsquo;desi&rsquo; &nbsp;and &lsquo;kabuli&rsquo; types ranged between 0 to 28.5% and late wilting ranged between 0 to 100%. In &lsquo;kabuli&rsquo; type chickpea, 10 genotypes (IPCK2012-129, IPCK2012-141, IPCK2012-258, IPCK2012-306,IPCK2012-132, IPCK2012-137, IPCK2012-138, IPCK2012-140, IPCK2012-143, IPCK2012-144)) and in &lsquo;desi&rsquo; type, 15 genotypes(IPC2012-03, IPC2012-10, IPC2012-20 and IPC2012-28, IPC2012-02, IPC2012-04, IPC2012-05, IPC2012-13, IPC2012-18, IPC2012-19, IPC2012-21, IPC2012-24, IPC2012-25, IPC2012-26 and IPC2012-29) were found highly resistant/ resistant. Local severity index (LSI) was higher for land races (71.7%) compared to elite breeding lines (27.8%). Among elite breeding lines least LSI was noticed in &lsquo;desi&rsquo; type (23.6%) in comparison to &lsquo;kabuli&rsquo; type genotypes (32.1%). In the present study, high level of resistance was observed in elite breeding lines compared to land races. The genotypes found resistant to wilt in the present study may be exploited for development of Fusarium wilt resistant varieties.

New sources of resistance in land races and advance germplasm against Fusarium oxysporum f. sp. ciceris &nbsp;race 2 causal agent of chickpea wilt &nbsp;

<div>Background: Urdbean (2n=2x=22), also known as blackgram is an important short duration legume crop belonging to family Fabaceae, widely cultivated in Asia. Urdbean occupies an important position among pulses owing to its high seed protein (25-26%), carbohydrates (60%), fat (15%), minerals, amino acids and vitamins. Owing to its low water requirement, it is also suitable for rainfed conditions. &nbsp;It adapts well to various cropping systems owing to its ability to fix atmospheric nitrogen in symbiosis with soil bacteria, rapid growth and early maturity. Half diallel analysis was adopted in present study to gather information on gca (general combining abilities) and sca (specific combining abilities) of 6 diverse parents and simultaneously estimating various types of gene effects involved in the expression of seed yield and related attributes in urdbean. 
 
Methods: The F1&rsquo;s were developed during 2017 in 9 x 9 half diallel fashion by Sharma et al. 2019 and these F1&rsquo;s were evaluated. Significant crosses on the basis of gene action and combining ability were selected for further advancement. The experimental material comprised of the six parents and 15 F2&rsquo;s of a 6 x 6 half diallel cross among six cultivars of urdbean (four are purelines viz., Palampur-93, HPBU-111, DU-1 and KU-553 and rest of the two are advanced and indigenous lines viz., Him Mash-1 and IC-281994). The F2&rsquo;s along with the parental genotypes were grown in a Randomized block Design (RBD) with three replications at Experimental Farm of the Department of Crop Improvement, COA, CSK HPKV Palampur (H.P.) during Kharif, 2018. 
 
Result: &nbsp;The cross combination, Him Mash-1&times; HPBU-111, was identified the best for high seed yield on the basis of sca. The specific crosses, Palampur-93 &times; IC-281994, Palampur-93 &times; KU-553 were good specific combiners for most of the traits viz., plant height, branches per plant, pods per plant, biological yield per plant, seed yield per plant, harvest index, 100-seed weight and crude protein content.</div>

Combining Ability and Gene Action Analysis for Seed Yield and Component Traits in F2 Generation of Vigna mungo L. Hepper by using Griffing Approach

<div>Background: The objective of the present study was to confirm the presence of CPV-2 in dogs with acute gastroenteritis and to characterize the antigenic variants circulating in the Aizawl region of Mizoram, India.&nbsp; 
 
&nbsp;</div>

<div>Methods: A hospital based epidemiological study was carried out from April, 2019 to January, 2020. Faecal samples were collected from the dogs with gastroenteritis and screened for CPV-2 infection by polymerase chain reaction (PCR). The distribution of positive cases according to various epidemiological factors was studied. Partial sequencing of VP2 gene was performed for the analysis of CPV-2 variants.&nbsp; 
 
Result: A total of 96 faecal samples were collected during the study period out of which 70 (72.91%) were found positive for CPV-2 infection. The distribution of positive cases was highest in young dogs of the age group between 3-6 months (47.14%), cross-bred (48.57%) and unvaccinated dogs (64.28%). The percentage of CPV-2 infection was relatively higher in male (54.28%) as compared to female dogs (45.71%). The analysis of nucleotide sequences from amplified products and phylogenetic analysis revealed presence of CPV-2a (1/5, 20.0%) and CPV-2c (4/5, 80.0%). Furthermore, sequence analysis of large number of samples is required to ensure the prevalent antigenic variant of CPV-2 linked to the infection.</div>

​Molecular Characterization and Phylogenetic Analysis of Canine Parvovirus Type 2 (CPV-2) in the Aizawl Region of Mizoram Reveals Circulation of CPV-2c Antigenic Variant: A Hospital based Study

Background: A 60-day experiment was conducted to evaluate the combined effect of salinity and Ca2+: Mg2+ ratio on the growth performance and survival of Penaeus vannamei reared in inland saline ground water (ISGW) at ICAR-Central Institute of Fisheries Education (CIFE), Rohtak Centre, Haryana, India. 
 
Methods: The study used three different salinities viz. T1 (5 ppt), T2 (10 ppt) and T3 (15 ppt) with four different level of Ca2+: Mg2+ rations such as 1:1, 1:2, 1:3 and 1:4. juveniles of P. vannamei with average body weight of 3.70&plusmn;0.02 g, were stocked in 100 L capacity of circular plastic tanks. Total 36 experimental tanks were used as experimental unit. The stocking densities were 20 animals in each tank and each treatment were kept in triplicate followed the factorial design (3&times;4). 
 
Result: P. vannamei expressed better growth performance in terms of SGR, FCR, FER and PER in the T2 and T3 fortified Ca2+: Mg2+ ratio of 1:3. Lowest growth observed in T1 fortified with Ca2+: Mg2+ ratio 1:1. The study found 100% survival in T2 and T3 fortified with Ca2+: Mg2+ ratio of 1:3 compared with other treatment groups, which showed &lt;80% survival. Based on the results, it can be concluded that the better growth performance, survival of P. vannamei observed in 10 and 15 ppt salinities of ISGW fortified with 1:3 ratio of Ca2+: Mg2+.

Effects of Salinity and Ca2+: Mg2+ Ratio on Growth Performance and Survival of Penaeus vannamei (Boone, 1931) Reared in Inland Saline Ground Water

Background: A 60-day experiment was conducted to evaluate the combined effect of salinity and Ca2+: Mg2+ ratio on the nutrient profile, physiological responses, and clinical signs of Penaeus vannamei reared in inland saline ground water.&nbsp; 
 
Methods: The study used three different salinities viz. T1 (5 ppt), T2 (10 ppt) and T3 (15 ppt) with four different levels of Ca2+: Mg2+ ratios such as 1:1, 1:2, 1:3, and 1:4. A total of 720 healthy post larvae of P. vannamei (mean body weight of 3.70&plusmn;0.02 g) were stocked (20 shrimp/tank) in 36 circular plastic tanks (100 L capacity each). Each treatment was triplicated following the 3 &times; 4 factorial design. 
 
Result: A significant increase of protein and ash contents and decrease of moisture content were noticed with increasing salinity. The study found no significant difference in the carbohydrate and crude lipid content of P. vannamei. A linear relationship between salinity and serum osmolality was observed which indicated significant increase of osmoregulatory capacity with increasing salinity. The treatment groups fortified with deficient level of Ca2+: Mg2+ ratio showed prominent changes such as abdominal white muscle on dorsal side and muscle cramps. Based on the results, it can be concluded that the better physiological adoption of P. vannamei was observed in 10 and 15 ppt salinities of ISGW fortified with Ca2+: Mg2+ ratio 1:3.

Effects of Salinity and Ca2+: Mg2+ Ratio on Nutrient Profile, Physiological Responses and Clinical Signs of Penaeus vannamei (Boone, 1931) Reared in Inland Saline Ground Water

Effect of F₂ Inter se Mating on Quantitative Traits Mean, Range, Variance and Heritability in Dolichos Bean (Lablab purpureus L. Sweet var. Lignosus)

Genetic Analysis of F₂ Populations for Quantitative Traits in Blackgram [Vigna mungo (L.) Hepper]

Transgressive Segregants in F₂ Populations of Three Superior Crosses viz., ML 267×LGG 528, MGG 390×LM 95, LM 95×EC 362096 in Mungbean

Combining Ability Studies for Seed Yield and its Quantitative Traits in F₂ Crosses of Mungbean [Vigna radiata (Wilczek)]

Study of Genotypic and Phenotypic Variation in F₂ Segregating Generation of Okra [Abelmoschus esculentus (L.) Moench]

New sources of resistance in land races and advance germplasm against Fusarium oxysporum f. sp. ciceris race 2 causal agent of chickpea wilt

Combining Ability and Gene Action Analysis for Seed Yield and Component Traits in F₂ Generation of Vigna mungo L. Hepper by using Griffing Approach

Molecular Characterization and Phylogenetic Analysis of Canine Parvovirus Type 2 (CPV-2) in the Aizawl Region of Mizoram Reveals Circulation of CPV-2c Antigenic Variant: A Hospital based Study

Effects of Salinity and Ca²⁺: Mg²⁺ Ratio on Growth Performance and Survival of Penaeus vannamei (Boone, 1931) Reared in Inland Saline Ground Water

Effects of Salinity and Ca²⁺: Mg²⁺ Ratio on Nutrient Profile, Physiological Responses and Clinical Signs of Penaeus vannamei (Boone, 1931) Reared in Inland Saline Ground Water