Seed quality status of rice varieties based on physical properties, seed health and proximate composition

In the present study, seed quality status of fifteen rice varieties were evaluated for physical properties, health status and proximate composition. Physical properties like moisture content, seed purity, germination and vigor index varied between 11.77-14.67%, 96.08-98.93%, 96.50 to 99.00% and 1972.74 to 2639.76, respectively. The shoot length and root length of seedlings were from 8.93 cm to 12.99 cm and 10.89 cm to 14.22 cm, respectively. Seed health was determined by blotter test method. Five seed-borne fungi were detected and the identified fungi were Bipolaris oryzae (1.00-8.50%.), Fusarium moniliforme (0.50-3.50%), Fusarium oxysporum (0.50-9.00%.), Curvularia lunata (0.00-7.50%) and Alternaria padwickii (0.00-4.00%). Proximate composition analysis assessment was done using Association of Official Analytical Chemists (AOAC) method. The dry matter, ash, crude fiber, crude protein, crude fat and carbohydrate were between 92.52- 93.77%, 2.39-6.70%, 8.65-14.27%, 6.51-9.13%, 1.23-1.97% and 62.84-71.06%, respectively

Effect of salt stress on growth of sorghum germplasms at vegetative stage

Soil salinity is an increasing problem in the world and main obstacle to agricultural productivity especially in areas where irrigation is necessary. It adversely affects plant growth and development. Adoption of salt tolerant variety is more important here and so screening of salt tolerant germplasms is essential. For this reason, a germination test under salinity and a hydroponic experiment were conducted at Plant Physiology Laboratory, Department of Crop Botany, Bangladesh Agricultural University, Mymensingh to investigate the effect of NaCl on germination, morphological characters and growth of sorghum seedlings. The experiment comprised of two levels of NaCl concentration viz. Control (without NaCl and EC 1.36 dSm−1 in hydroponic culture) and 80 mM NaCl and five sorghum germplasms viz. BD 700, BD 703, BD 707, BD 710 and BD 726. There were 10 (5×2) treatments in a completely randomized design (CRD) with three replications. Results showed that germination percentage, hypocotyls and epicotyls length, root and shoot length, leaf length, leaf sheath length, fresh and dry mass production were influenced by NaCl stress. However, among tested germplasms, BD 707 showed the best performance considering the seedlings growth, germination percentage and other parameters. BD 710 and BD 703 showed the highest sensitivity to NaCl stress based on the above parameters studied. These results suggested that sorghum is able to grow with moderate salinity

Effect of moisture stress on morphological and yield attributes of four sorghum varieties

Drought adversely affects growth and yield of crops to various extents. Growing of drought tolerant crops is a good option to obtain economical yields from water stress areas for which quick method to screen drought tolerant plants, particularly in early stages of their growth is important. For this reason, a field experiment was conducted to evaluate the genetical potential to drought tolerance of four sorghum varieties viz Hybrid Sorgo, Safal, BD 731, BD 740. The experiment was laid out in a split plot design with three replications. The plants were grown under three drought levels viz. 100% FC (control), 70% FC and 40% FC. Growth and yield of the Sorghum varieties were found to be decreased gradually with gradual increase in drought levels as compared to the control. This reduction was associated with decreased yield components. Water stress also decreased protein and starch content. The variety BD 740 followed by BD 731 showed the better performance in respect of no. of grains panicle-1, panicle dry weight, 1000-grain weight, grain yield hill-1, protein content and starch content than Hybrid Sorgo and Safal at same water stress condition. Therefore Bangladeshi varieties were found more tolerant than Hybrid Sorgo variety to water stress. Findings of this research will be helpful for the farmers about the beneficial use of resource in terms of managing limited water as well as increasing crop productivity. Finally these research findings would certainly contribute food security in Bangladesh

Effect of salinity on morpho-physiological traits at reproductive stages of Oryza sativa

Soil salinity is one of the most adverse environmental problems which restricts crop yield. Salinity affects rice plants very badly from germination to its maturity. Therefore, a pot experiment was conducted to study the salinity tolerance of rice genotypes viz. SAL655, STL15, PBRC37, Binadhan-8 and BRRI dhan28. The plants were grown under four salinity levels (0, 6, 9 and 12 dSm−1). Plant height, total number of green leaves hill−1, root dry weight, stem dry weight, total dry weight per hill, root shoot ratio was found to be decreased gradually with gradual increase in salinity levels as compared to the control. The genotype Binadhan-8 and PBRC37 showed the better performance in respect of all the parameters than other genotypes. Therefore, Binadhan-8 and PBRC37 were found more tolerant than other genotypes to salt stress

Characterization of maize hybrids (Zea mays L.) for detecting salt tolerance based on morpho-physiological characteristics, ion accumulation and genetic Variability at early vegetative stage

Increasing soil salinity due to global warming severely restricts crop growth and yield. To select and recommend salt-tolerant cultivars, extensive genotypic screening and examination of plants’ morpho-physiological responses to salt stress are required. In this study, 18 prescreened maize hybrid cultivars were examined at the early growth stage under a hydroponic system using multivariate analysis to demonstrate the genotypic and phenotypic variations of the selected cultivars under salt stress. The seedlings of all maize cultivars were evaluated with two salt levels: control (without NaCl) and salt stress (12 dS m−1 simulated with NaCl) for 28 d. A total of 18 morpho-physiological and ion accumulation traits were dissected using multivariate analysis, and salt tolerance index (STI) values of the examined traits were evaluated for grouping of cultivars into salt-tolerant and -sensitive groups. Salt stress significantly declined all measured traits except root–shoot ratio (RSR), while the cultivars responded differently. The cultivars were grouped into three clusters and the cultivars in Cluster-1 such as Prabhat, UniGreen NK41, Bisco 51, UniGreen UB100, Bharati 981 and Star Beej 7Star exhibited salt tolerance to a greater extent, accounting for higher STI in comparison to other cultivars grouped in Cluster-2 and Cluster-3. The high heritability (h2bs, >60%) and genetic advance (GAM, >20%) were recorded in 13 measured traits, indicating considerable genetic variations present in these traits. Therefore, using multivariate analysis based on the measured traits, six hybrid maize cultivars were selected as salt-tolerant and some traits such as Total Fresh Weight (TFW), Total Dry Weight (TDW), Total Na+, Total K+ contents and K+–Na+ Ratio could be effectively used for the selection criteria evaluating salt-tolerant maize genotypes at the early seedling stage

Boron-mediated aluminium stress tolerance under aluminium toxicity at germination and early seedling stages of wheat

Aluminium stress is one of the major problems of wheat production that significantly reduces the growth and development. Al toxicity can be recovered by exogenous application of different growth inducing nutrient elements. Thus, this study was conducted to evaluate the ameliaration effect of B under Al toxicity. Therefore, a petri dish and hydroponic culture experiment of wheat was conducted at Crop Physiology Laboratory, Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during the period from January 2016 to February 2017 to investigate the effect of boron on amelioration of aluminium toxicity in germination and seedling stage. Both the experiments were designed in completely randomized design (CRD) with three replications. The experiments were comprised of four levels of boron and aluminium concentrations viz., 0 µM B + 0 µM Al (control), 0 µM Al + 40 µM B, 200 µM Al + 40 µM B and 0 µM B + 200 µM Al and five wheat varieties viz; BARI Gom-23, BARI Gom-24, BARI Gom-28, BARI Gom-27 and BARI Gom-30. Results indicated that germination percentage, radicle and plumule length, root and shoot length, leaf length, fresh and dry mass plant-1 were greater in 0 µM Al + 40 µM B treated plants than 0 µM B + 200 µM Al induced conditions. It indicates that wheat seedlings are susceptible to aluminium and boron can ameliorate aluminium toxicity. However, among the studied varieties, the reduction of dry mass under aluminium stress was minimum in BARI Gom-28 followed by BARI Gom-23 indicating BARI Gom-28 was more tolerant to aluminium stress than the other varieties. On the contrary, the varieties, BARI Gom-27 and BARI Gom-24 were more susceptible to aluminium stress. So it indicates that aluminium stress severely affects the growth and developments especially in the sensitive varieties and tolerant varieties have the self-ability to grow and develop even under aluminium stress condition

Genotypic divergence, photosynthetic efficiency, sodium extrusion, and osmoprotectant regulation conferred salt tolerance in Sorghum

Salt stress is one of the major limitations to modern agriculture that negatively influences plant growth and productivity. Salt tolerant cultivar can provide excellent solution to enhance stress tolerance with plant fitness to unfavorable environments. Therefore, this study was aimed to screen salt tolerant sorghum genotypes through evaluating of different morphological, biochemical, and physiological attributes in response to salinity stress. In this study, we have been evaluated total six sorghum genotypes including Hybrid sorgo, Debgiri, BD-703, BD-706, BD-707, and BD-725 under salt stress (12 dS m−1 NaCl). The response variables included length and weight of root and shoot, root: shoot ratio (RSR), photosynthesis (A), transpiration rate (E), elemental concentrations (K+ , Na+ and K+ /Na+ ), photochemical efficiency of photosystem II (Fv/Fm), water use efficiency (WUE) and pigment content (chlorophyll a, and b). The results revealed that saline environment significantly reduced all response variables under study of sorghum genotypes, however, Hybrid sorgo remained unmatched by recording the maximum root and shoot traits. The same genotype recorded higher photosynthetic efficiency which was attributed to Na+ extrusion, K+ uptake and higher K+ /Na+ ratio (1.8 at stress), while these mechanisms were not fully active in rest of genotypes. Moreover, this study also implies the involvement of proline in imparting tolerance against saline environment in Hybrid sorgo genotype. Overall, BD-703 remained the most salt sensitive genotype as evident from the minimum morphological growth traits and the least biosynthesis of osmoprotectants. These findings open new research avenues for salt stress alleviation by identifying elite salt-tolerant genotypes of sorghum for breeding programs