Drought Tolerance in Mung Bean is Associated with the Genotypic Divergence, Regulation of Proline, Photosynthetic Pigment and Water Relation

Drought is one of the critical conditions for the growth and productivity of many crops including mung bean(Vigna radiata L.Wilczek).Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security.In this context,the study investigated the physiological and biochemical responses of four drought tolerant(BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7),and four drought sensitive(BARI Mung-1,BARI Mung-3,BU Mung-4,BMX-05001)mung bean genotypes under wellwatered(WW)and water deficit(WD)conditions.The WW treatment maintained sufficient soil moisture(22%±0.5%,i.e.,30%deficit of available water)by regularly supplying water.Whereas,the WD treatment was maintained throughout the growing period,and water was applied when the wilting symptom appeared.The drought tolerant(DT)genotypes BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7 showed a high level of proline accumulation(2.52–5.99 mg g^(−1) FW),photosynthetic pigment(total chlorophyll 2.96–3.27 mg g^(−1) FW at flowering stage,and 1.62–2.38 mg g^(−1) FW at pod developing stage),plant water relation attributes including relative water content(RWC)(82%–84%),water retention capacity(WRC)(12–14)as well as lower water saturation deficit(WSD)(19%–23%),and water uptake capacity(WUC)(2.58–2.89)under WD condition,which provided consequently higher relative seed yield.These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions.Furthermore,the genotype BMX-08010-2 showed superiority in terms of those physio-biochemical traits,susceptibility index(SSI)and stress tolerance index(STI)to other genotypes.Based on the physiological and biochemical responses,the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress,and subsequently,it could be recommended for crop improvement through hybridization programs.In addition,the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.

Improvement of Early Maturing and Climate Resilient Chickpea (Cicer arietinum L.) Cultivars Suitable for Multiple Environments in Bangladesh

Ensuring food security for the rapidly increasing population and changing climatic scenarios are requisites for exploiting the genetic divergence of food crops.A study was undertaken to sort out an early maturing chickpea variety for fitting easily between rice-rice cropping systems in the Eastern Indo-Gangetic Plain of Bangladesh.The trial was comprised of eight elite lines of chickpea and executed at various localities in Bangladesh from 2014–15 to 2017–18.The result explored the chickpea genotype,BARI Chola-11 remained superior to the rest of the elite genotypes for having a short maturity period(100–106 days),and lesser days to 50%flowering(47–55 days).The same genotype was recorded to have robust vegetative and reproductive yield attributes including plant height(49–57 cm),podsplant−1(37–50),and optimum 100 seed weight(19.5–20.6 g).Owing to better yield attributes,BARI Chola-11 resulted in the maximum seed yield(1200–1500 kg ha-1)of chickpea and might be recommended for general adoption in the region for boosting nutritional security status through improved productivity under changing climate.

Inheritance of Resistance to Mungbean Yellow Mosaic Virus (MYMV) in Inter and Intra Specific Crosses of Mungbean (<i>Vigna radiata</i>)

The objective of this research was to study the mode of inheritance of resistance to mungbean yellow mosaic virus (MYMV) in inter TNAU RED × VRM (Gg) 1 and intra KMG 189 × VBN (Gg) 2 specific crosses of mungbean. An infector row technique was used for evaluating parents, F1, F2 and F3 plants for MYMV resistance. No insecticide was sprayed in order to maintain the natural whitefly population in experimental field. In the field condition, only after 80% of plants showed MYMV incidence, and the scoring of the test materials was done by MYMV disease rating scale. According to the mean disease score, the mungbean genotypes were categorized into five groups resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) and highly susceptible (HS). 3 (Susceptible): 1 (Resistance) was observed in all two crosses of all F2 population and it showed that the dominance of susceptibility over the resistance and the results of the F3 segregation (1:2:1) confirm the segregation pattern of the F2 segregation. Collectively all the two crosses F2 and F3 generations results suggested that a single recessive gene is involved in resistance against the MYMV disease.

Agro-Morphological Characterization and Genetic Dissection of Linseed(Linum usitatissimum L.)Genotypes

Linseed is a multipurpose crop and the crop needs further improvement to increase production and yield due to its high value and demand.This study aimed to assess the extent and pattern of genetic variability of forty linseed genotypes based on diverse agro–morphological and yield attributes.The field experiment was conducted following a Randomized Complete Block Design with three replications.Linseed germplasm showed a wide range of phenotypic expression,genetic variability and heritability for 30 studied traits.A low to high phenotypic coeffi-cient of variation(PCV)and genotypic coefficient of variation(GCV)were observed.The lowest genotypic(σ2 g)and phenotypic variances(σ2 p)were found in capsule diameter(CD),length of calyx(LC),capsule length(CL),seed length(SL),and seed breadth(SB).High broad-sense heritability(h2 b)with high genetic advance as a percentage of mean(GAM)were observed in days to germination started(DGS),days to 80%emergence(DE),plant height at 28 and 40 DAS,number of flowers(NFPP),filled capsules(NFCPP)and yield per plant(YPP)indicating additive gene action exists for these characters.Hierarchical cluster analysis separated 40 genotypes into five clusters,where Clusters I to V assembled with 13,4,4,5 and 14 genotypes,respectively.Considering yield and yield attributes,Cluster-IV(G3,G4,G6,G10 and G31)genotypes showed promising while,Cluster-II(G2,G16,G35,G36)and Cluster-III(G1,G33,G39 and G40)genotypes were dominant on plant morphological traits.Based on principal component analysis(PCA),few characters such as YPP,NFPP,NFCPP,days to first flowering and capsule formation,early emergence,days to branch initiation and plant heights at different growth stages revealed important and effective traits for consideration in the selection of linseed breeding programs.

More Benefit from Less Land： A New Rice-Pea-Rice Cropping Pattern for Resource-Poor Farmers of Bangladesh

The experiments were conducted at the Pulses Research Centre, Ishurdi, Pabna, Bangladesh during the 2005-2006 and 2006-2007 crop seasons to determine the economic viability of planting legumes for both vegetable and forage purposes in the fallow period between monsoon-rice and spring-rice. The objectives were to ensure better land utilization, break up the mono cropping, improve soil health, and generate extra-income for small and resource-poor farmers of Bangladesh. Crop compositions used in the experiments were monsoon-rice （cv. BRRIdhan-32, BRRldhan-39 and BINAdhan-4） followed by pulses （grasspea, chickpea and field pea） followed by spring-rice （cv. BRRldhan-28, BRRldhan-29 and BINAdhan-6）. Based on the data from two years in a pooled analyses, it was observed that monsoon-rice variety BINAdhan-4, followed by field pea （as vegetable ＆ forage） and spring-rice variety BINAdhan-6 produced the highest yields of 5.0 t ha-1 rice grain, 3.25 t ha1 （green vegetable） ＋ 18.1 t hal （forage） legumes and 7.8 t ha~ rice grain, respectively. The cropping pattern of monsoon-rice （BINAdhan-4）-field pea （as vegetable ＋ forage）-spring-rice （BINAdhan-6） gave the highest net return of USD$1,705 hal year-~ compared to other patterns with different rice varieties and chickpea and grasspea. This is a new finding, and is being practiced by farmers of Bangladesh who have enhanced their farm income substantially. This has also generated job opportunities for rural women to pick the green vegetable of field pea.

The Outbreeding Enhancement and Correlation Studies in F₁Hybrids of Hexaploid Wheat (<i>Triticum aestivum</i>L.) Cultivars

The current study was conducted in the experimental field of the Department of Biotechnology and Genetic Engineering, Faculty of Life Science, University of Development Alternative, Dhaka, Bangladesh during the winter season 2017-2018. The study was performed to reduce the heterotic effect and phenotypic correlation among numerous yield characters for F1 hybrids of hexaploid wheat (Triticum aestivum L.). The experimental design has consisted of six parental variants (Sonalika, Balaka, Prodip, Kanchan, Agrahani and Protiva), which were crossed and nine possible cross combinations (F1 hybrids) (Prodip × Agrahani, Balaka × Agrahani, Prodip × Protiva, Protiva × Agrahani, Agrahani × Kanchan, Kanchan × Sonalika, Protiva × Prodip, Sonalika × Agrahani, and Prodip × Kanchan) were obtained. The experimental fields were selected and arranged in a randomized complete block design with four replicates, where eight characters were studied. The mean square of the analysis of variance showed that the hybrids differed significantly (p ≤ 0.01) for all studied characters except for maturity to 75% of days and height of the plant, while the parents only had no differences in grain yield. The mean square of the parent and the F1 hybrid indicated that considerable heterosis existed in the F1 hybrids. In general, correlation coefficients indicated that the maturity to 75% of days was significant but negatively correlated with most of the yield traits, suggesting that the genotypes which became mature early may have lower yields. Plant height was also negatively correlated with grain spike−1, seed index, and harvest index. The grain yield plant−1 was significant and positively correlated with all yield traits. Correlation indicates that single or multiple production-related ingredients can be used as selection time to select plants with higher yield traits with larger grains.