Cooking and Eating Quality Profiling of Some Popular Rice Cultivars In Bangladesh

Eating and cooking quality of rice plays major role in consumer’s preference for any cultivar. In the present investigation 21 popular rice cultivars were analyzed for their cooking and eating quality traits. Moderate variations were observed for all the traits studied except solid in cooking water. Among the cultivars, cooking time ranged from 14.02 to 21.37 minutes, water uptake ratio from 2.24 to 3.324 %, solid in cooking water from 1.027 to 1.049 gm, volume expansion ratio from 2.8 to 4.28 %, % amylose content from 17.367 (low) to 27.387(intermediate), protein content from 6.28 to 8.96 (%), and most of the cultivars were found with intermediate gelatinization temperature. Solid in cooking water was found positively correlated with cooking time, but negatively with water uptake ratio.  Considering the preferences for cooked rice, high amylose content and low to intermediate gelatinization temperature of BRRI rice29, BRRI rice49 and Binarice-11 justified their popularity among the farmers and consumers

Differential role of spermine and thermospermine in Arabidopsis thaliana in response to abiotic stresses

Polyamines (PA) are small organic polycations found in all living organisms. Putrescine (Put), spermidine (Spd), spermine (Spm) and thermospermine (T-Spm) are the most abundant PAs in plants. Of the polyamines (PAs) plant contains at least two types of tetraamines; spermine (Spm) and thermospermine (T-Spm) and they seem to have different functions in plants. The experiment was conducted to eludicate the stress responsive roles of Spm and T-Spm using wild ecotype (Col-0) and three different knockout mutants (spms, acl5 and spms/acl5) of Arabidopsis, differing in the amount of spermine and thermospermine content. First exogenous pretreatment of both tetraamines showed their different effects on plant phenotype including root and shoot length, cholorophyll content both under normal and salt stressed condition. The effect of exogenous T-Spm was more effective than Spm in plant growth and stress tolerance. The mutants varying in endogenous tetraamines content were also found to be different in response to stress (salt, osmotic and ionic) condition. Growth inhibition of spms mutant seedlings was minimum in compare to other mutants and wild type, probably due to higher amount of T-Spm content. Further to differentiate the tissue specific expression of tetraamines, histochemical GUS assay was performed using SPMS and ACL5 promoter:: GUS transgenic plants and the results indicate that the two tetraamines; spermine and thermospermine may play some different and specific role in respect to tissue specificity and stress responses

Potential determinants of salinity tolerance in rice (Oryza sativa L.) and modulation of tolerance by exogenous ascorbic acid application

Rice is a relatively salt-sensitive crop with the reproductive and seedling stages being the most sensitive. Two separate experiments were conducted to isolate potential determinants of salinity tolerance and to investigate the possibility of modulating salt tolerance by exogenous ascorbic acid (AsA) application. Rice plants were imposed to salinity (EC= 10.0 dS m-1) both at the seedling and reproductive phases of growth. Salinity at the seedling stage resulted a sharp decline in shoot and root growth related traits including leaf chlorophyll content, while hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels increased. Plants experienced with salinity at the reproductive phases of growth showed a significant reduction in yield attributing traits while the tissue levels of H2O2 increased. Exogenous AsA application reversed the negative impact of salt stress, modulating the root and shoots growth and yield related traits and lowering H2O2 and MDA levels. FL-478 was identified as the most tolerant genotype at the seedling stage, with Binadhan-10 being the most tolerant at the reproductive stage. Grain yield panicle-1 significantly and positively corrected with number of filled grains panicle-1, panicle length, plant height, and spikelet fertility, and negatively correlated with H2O2 levels. Stress tolerance indices clearly separated the tolerant and susceptible genotypes. A principal component analysis revealed that the first two components explained 87% of the total variation among the genotypes. Breeding efforts could therefore to undertake for developing salinity tolerance by manipulating endogenous AsA content in rice

Cooking and eating quality profiling of some popular rice cultivars in Bangladesh

Eating and cooking quality of rice plays major role in consumer’s preference for any cultivar. In the present investigation 21 popular rice cultivars were analyzed for their cooking and eating quality traits. Moderate variations were observed for all the traits studied except solid in cooking water. Among the cultivars, cooking time ranged from 14.02 to 21.37 minutes, water uptake ratio from 2.24 to 3.324 %, solid in cooking water from 1.027 to 1.049 gm, volume expansion ratio from 2.8 to 4.28 %, % amylose content from 17.367 (low) to 27.387(intermediate), protein content 6.28 to 8.96 (%), and most of the cultivars were found with intermediate gelatinization temperature. Solid in cooking water was found positively correlated with cooking time, but negatively with water uptake ratio.  Considering the preferences for cooked rice, high amylose content and low to intermediate gelatinization temperature of BRRI rice29, BRRI rice49 and Binarice-11 justified their popularity among the farmers and consumers