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Investigation of root system architecture (RSA) has a huge potential to support the crop improvement under suboptimal nutrient and water conditions. The present study was carried out using eight genotypes of each mungbean and urdbean for comparative analysis of RSA traits among the genotypes. Presence of significant variations and medium to high heritability was observed for RSA traits. The genotypes KM 12-29 followed by PUSA 9072 among the mungbean genotypes and LBG 623 followed by PU 11-14 among the urdbean genotypes showed higher proportion of RSA traits. The higher percentage distribution of root traits was observed under diameter intervals in the order of 0-0.5 > 0.5-1.0 > 1.0-1.5 > 1.5-2.0 >> 2.0 mm in both mungbean and urdbean genotypes. Thus, the study shows the clear depiction and comparison of RSA traits among mungbean and urdbean genotypes, which can be exploited for cultivar development in future breeding programmes. Bangladesh J. Bot. 52(1): 61-69, 2023 (March)

Background: Phosphorus (P) is the essential nutrient required for the growth and development of plants. P deficiency mainly leads to dark green foliage, alteration of root architectural traits and higher root to shoot ratio in plants. Further P deficiency results in enhancement of reactive oxygen species (ROS), thereby it leads to oxidative damage to plant cells. Plants have developed the mechanisms like production of antioxidants to overcome this effect. Methods: In the present study, 18 genotypes were evaluated under a hydroponic system with normal and low P levels. After 21 days, the seedlings were used for investigating the physiological and antioxidant activity response of genotypes under normal and low P condition. Result: The mean values of traits chlorophyll concentration, root dry weight, root to shoot ratio, H2O2, FRAP and DPPH were significantly higher under low P condition compared to normal P condition. The correlation and principal component analysis revealed that the traits RDW and TDW are major contributors to variation and could be used for P deficiency screening in mungbean. Based on major contributing traits of variation, the genotypes PUSA 1333 was identified as an efficient genotype and could be used in P use efficiency improvement in mungbean.

NDLH 2051-1 has a mean seed cotton yield potential of 1590 kg ha-1 and has been singled out for commercial cultivation in the south and central zones of India by the Regional Agricultural Research Station, Nandyal, India. This cultivar represents an essential contribution to sustainable cotton production in India.

Phosphorus (P) is one of the major constraints for crop growth and development, owing to low availability and least mobility in many tropical soil conditions. Categorization of existing germplasm under P deficient conditions is a prerequisite for the selection and development of P efficient genotypes in the mungbean. In the present investigation, 36 diverse genotypes were categorized for phosphorus use efficiency traits using four different techniques for identification of phosphorus use efficient mungbean genotypes. The studied genotypes were categorized for P efficiency based on efficiency, responsiveness, and stress tolerance score of genotypes under normal and low P conditions. The mean values of traits, root dry mass, root to shoot ratio, and P utilization efficiency are significantly higher under low P conditions indicating the high responsiveness of traits to P deficiency. The presence of significant interaction between genotypes and P treatment indicates the evaluated genotypes were significantly affected by P treatment for studied traits. The total P uptake showed significant and positive correlations with root dry mass, shoot dry mass, total dry mass,and P concentration under both P regimes. Out of the four techniques used for the categorization of genotypes for P efficiency, three techniques revealed that the genotype PUSA 1333, followed by Pusa Vishal, PUSA 1031, and Pusa Ratna is efficient. The categorization based on stress tolerance score is the finest way to study variation and for the selection of contrasting genotypes for P efficiency. The identified P efficient genotypes would be valuable resources for genetic enhancement of P use efficiency in mungbean breeding.

The development of phosphorus-efficient crop cultivars boosts productivity while lowering eutrophication in the environment. It is feasible to improve the efficiency of phosphorus (P) absorption in lentils by enhancing phosphorus absorption through root architectural traits. The root architectural traits of 110 diverse lentil genotypes of Indian and Mediterranean origin were assessed, and the relationships between traits were investigated. In a hydroponics experiment, the lentil lines were examined at the seedling stage under two conditions: adequate P supply and deficient P supply. The Pearson correlation coefficients between root architectural traits and genetic diversity among lentil lines were assessed. To estimate variance components, a model (fixed factor) was used. In this experiment, both phosphorus (P) and genotype were fixed variables. Our lentil lines showed significant genetic variability and considerable genetic diversity for all traits under both treatments. The TRL (total root length) and PRL (primary root length) showed strong positive associations with all other characteristics excluding root average diameter (RAD) in both P treatments. In both P treatments, the RAD revealed a negative significant association with Total Root Tips (TRT), as well as total root volume (TRV) and total root forks (TRF) in the deficit conditions of P. Total root volume (TRV), total surface area (TSA), and total root tips had higher coefficient variance values. The first two principal components represented 67.88% and 66.19% of the overall variance in the adequate and deficit P treatments respectively. The Shannon-Weaver diversity index (H′) revealed that RAD, PRL, and TSA had more variability than TRT and TRF under both treatments. According to the Comprehensive Phosphorus Efficiency Measure (CPEM), the best five highly efficient genotypes are PLL 18-09, PLS 18-01, PLL 18-25, PLS 18-23, and PLL 18-07, while IG112131, P560206, IG334, L11-231, and PLS18-67 are highly inefficient genotypes. The above contrasting diverse lentil genotypes can be utilized to produce P-efficient lentil cultivars. The lentil germplasm with potentially favorable root traits can be suggested to evaluated for other abiotic stress to use them in crop improvement programme. The scientific breakthroughs in root trait phenotyping have improved the chances of establishing trait–allele relationships. As a result, genotype-to-phenotype connections can be predicted and verified with exceptional accuracy, making it easier to find and incorporate favourable nutrition-related genes/QTLs in to breeding programme.

Phosphorus (P) deficiency is one of the serious problems affecting plant growth in mungbean in different parts of the world. The root, shoot and biomass related traits were investigated for identifying P-efficient genotypes in 54 mungbean genotypes under low-P (LP) and normal-P (NP) conditions. In this study, the membership function value of P use efficiency of studied traits was used as a compendious index for studying P use efficiency (PUE) in mungbean. Among the studied traits, mean values of total root volume, chlorophyll concentration, root dry weight (RDW) and root to shoot ratio increased >25% under LP condition indicating that these traits are highly responsive to P deficiency. Correlation and stepwise regression analysis revealed that RDW explained most of the variation and could be used as a clear indicator of PUE. The five highly P-efficient genotypes namely, MH 805, M 42, PUSA 9531, EC 398885 and M 209 with high MFVP values may be used for PUE improvement in mungbean.

Mungbean (Vigna radiata L. Wilczek) is an annual grain legume crop affected by low availability of phosphorus. Phosphorus deficiency mainly affects the growth and development of plants along with changes in root morphology and increase in root-to-shoot ratio. Deciphering the genetic basis of phosphorus use efficiency (PUE) traits can benefit our understanding of mungbean tolerance to low-phosphorus condition. To address this issue, 144 diverse mungbean genotypes were evaluated for 12 PUE traits under hydroponics with optimum- and low-phosphorus levels. The broad sense heritability of traits ranged from 0.63 to 0.92 and 0.58 to 0.92 under optimum- and low-phosphorus conditions, respectively. This study, reports for the first time such a large number of genome wide Single nucleotide polymorphisms (SNPs) (76,160) in mungbean. Further, genome wide association study was conducted using 55,634 SNPs obtained by genotyping-by-sequencing method. The results indicated that total 136 SNPs shared by both GLM and MLM models were associated with tested PUE traits under different phosphorus regimes. We have identified SNPs with highest p value (–log10(p)) for some traits like, TLA and RDW with p value (–log10(p)) of more than 6.0 at LP/OP and OP condition. We have identified nine SNPs (three for TLA and six for RDW trait) which was found to be present in chromosomes 8, 4, and 7. One SNP present in Vradi07g06230 gene contains zinc finger CCCH domain. In total, 71 protein coding genes were identified, of which 13 genes were found to be putative candidate genes controlling PUE by regulating nutrient uptake and root architectural development pathways in mungbean. Moreover, we identified three potential candidate genes VRADI11G08340, VRADI01G05520, and VRADI04G10750 with missense SNPs in coding sequence region, which results in significant variation in protein structure at tertiary level. The identified SNPs and candidate genes provide the essential information for genetic studies and marker-assisted breeding program for improving low-phosphorus tolerance in mungbean.

Mungbean (Vignaradiata L. Wilczek) is an early maturing legume grown predominantly in Asia for its protein-rich seeds. P deficiency can lead to several physiological disorders which ultimately result in a low grain yield in mungbean. The genetic dissection of PUpE (Puptake efficiency) and PUtE (P utilization efficiency) traits are essential for breeding mungbean varieties with a high P uptake and utilization efficiency. The study involves an association mapping panel consisting of 120 mungbean genotypes which were phenotyped for total dry weight, P concentration, total P uptake, and P utilization efficiency under low P (LP) and normal P (NP) conditions in a hydroponic system. A genotyping-by-sequencing (GBS) based genome-wide association study (GWAS) approach was employed to dissect the complexity of PUpE and PUtE traits at the genetic level in mungbean. This has identified 116 SNPs in 61 protein-coding genes and of these, 16 have been found to enhance phosphorous uptake and utilization efficiency in mungbeans. We identified six genes with a high expression (VRADI01G04370, VRADI05G20860, VRADI06G12490, VRADI08G20910, VRADI08G00070 and VRADI09G09030) in root, shoot apical meristem and leaf, indicating their role in the regulation of P uptake and utilization efficiency in mungbean. The SNPs present in three genes have also been validated using a Sanger sequencing approach.

Mungbean (Vigna radiataL.) is an important food grain legume, but its production capacity is threatened by global warming, which can intensify plant stress and limit future production. Identifying new variation of key root traits in mungbean will provide the basis for breeding lines with effective root characteristics for improved water uptake to mitigate heat and drought stress. The AVRDC mungbean mini core collection consisting of 296 genotypes was screened under modified semi-hydroponic screening conditions to determine the variation for fourteen root-related traits. The AVRDC mungbean mini core collection displayed wide variations for the primary root length, total surface area, and total root length, and based on agglomerative hierarchical clustering eight homogeneous groups displaying different root traits could be identified. Germplasm with potentially favorable root traits has been identified for further studies to identify the donor genotypes for breeding cultivars with enhanced adaptation to water-deficit stress and other stress conditions.

Roots enable the plant to survive in the natural environment by providing anchorage and acquisition of water and nutrients. In this study, root architectural traits of 153 mungbean genotypes were compared under optimum and low phosphorus (P) conditions. Significant variations and medium to high heritability were observed for the root traits. Total root length was positively and significantly correlated with total root surface area, total root volume, total root tips and root forks under both optimum P (r = 0.95, r = 0.85, r = 0.68 and r = 0.82 respectively) and low P (r = 0.95, r = 0.82, r = 0.71 and r = 0.81 respectively). The magnitudes of the coefficient of variations were relatively higher for root forks, total root tips and total root volume. Total root length, total root surface area and total root volume were major contributors of variation and can be utilized for screening of P efficiency at the seedling stage. Released Indian mungbean varieties were found to be superior for root traits than other genotypic groups. Based on comprehensive P efficiency measurement, IPM-288, TM 96-25, TM 96-2, M 1477, PUSA 1342 were found to be the best highly efficient genotypes, whereas M 1131, PS-16, Pusa Vishal, M 831, IC 325828 were highly inefficient. Highly efficient genotypes identified would be valuable genetic resources for P efficiency for utilizing in the mungbean breeding programme.

Highlights: • Occupancy of copper ions at about 20% towards tetrahedral sites. • Distribution is proposed on the basis of % of Fe ions at both A and B sites. • Distribution is checked by estimating the theoretical lattice constant values. - Abstract: The nanoparticles of Ni{sub 1−x}Cu{sub x}Zn{sub 0.35}Fe{sub 2}O{sub 4} were synthesized by sol–gel method using polyvinyl alcohol as a chelating agent. X-ray diffraction patterns of all the samples confirmed the single phase spinel structure. The site occupancy of copper in the nanosized nickel–zinc ferrite spinels was investigated with the help of in-field Mossbauer spectroscopy. Cation distribution for the whole series of compositions was proposed by considering the amounts of iron ions present at both tetrahedral and octahedral interstitial sites in the spinel lattice. Confirmation of the proposed distributions was done by estimating quantitatively the lattice parameters for these compositions and comparing their values with those of the experimentally observed ones.

This paper reports the synthesis and magnetic properties of single phase FeTiO3nanoparticles. Ilmenite nanoparticles are prepared through coprecipitation method. As prepared powder is amorphous in nature. When annealed inair and inert atmosphere, we get almost single phase pure crystalline FeTiO3. Our results show that FeTiO3in nanocrystalline form behaves like a weak ferromagnet below ~50 K while it is known that ilmenite is an antiferromagnet below ~55 K.