Thirty-one Aman rice germplasm were evaluated to assess their morphological variability and genetic diversity considering ten quantitative and thirty one qualitative traits at the field experimental plot of Bangladesh Institute of Nuclear Agriculture, Mymensingh, following randomized complete block design. The germplasm showed significant differences for all the studied traits. The highest grain yield/plant was recorded in Sentu-16 whereas the lowest was found in Gaindha. The genotypic coefficient of variation (GCV) was lower than those of the corresponding phenotypic coefficient of variation (PCV) for all the traits. High PCV and GCV along with heritability, genetic advance (GA) and GA in percentage of mean were recorded for number of filled grains/panicle and number of unfilled grains/panicle. Grain yield/plant had positively significant correlation with plant height, number of total tillers/hill, number of effective tillers/hill, number of filled grains/panicle and thousand grain weight. Path co-efficient analysis suggested that grain yield/plant had positive direct effect in association with days to fifty percent flowering, number of effective tillers/hill, panicle length, number of filled grains/panicle and thousand grain weight. Principal component analysis revealed that the first three components accounted for 79.57% of cumulative variance. Cluster analyses were revealed that the studied rice germplasm organized into five clusters based on D2 values where maximum inter-cluster distance was observed between cluster II and V. Qualitative characterization by distinctness, uniformity and stability test revealed that a wide range of variation was observed among the genotypes. Therefore, this study would be useful for breeders to choose and identify the revival and preservation of beneficial genes for crop improvement.

The study sought to evaluate the response of three groundnut genotypes (Binachinabadam-3, Dacca-1 and Zhingabadam) to various salt concentrations (D0 – Control, D1 – 2.5 dS/m, D2 – 5.0 dS/m, D3 – 7.5 dS/m, D4 – 10.0 dS/m, D5 – 12.5 dS/m) through observation of morphological and physiological characters. Based on relative performance of yield contributing characters and nutrient contents of leaves and stem, Binachinabadam-3 emerged to be a tolerant variety and based on root shoot characters, Dacca-1 appeared as tolerant while Zhingabadam always performed as sensitive variety. Salinity treatments had most adverse effects at flowering stage and followed the trend of sensitivity as flowering stage > vegetative stage> pre sowing stage > pod filling stage. All varieties were found to be tolerant up to salinity level of 7.5 dS/m.

No abstract

It is necessary to assess genetic diversity and a molecular characteristic among Bangladesh’s local rice cultivars. The purpose of the study was to assess the genetic diversity and molecular characterization of 83 rice landraces in Bangladesh using nine (9) SSR markers. A total of 262 allels were identified using nine (9) polymorphic markers. The highest number alleles 34 were identified by RM336 while the lowest was 13 by RM262. Polymorphism information content (PIC) value of each marker was evaluated on the basis of the number of alleles and it varied greatly for all the SSR loci tested. The PIC value ranged from 0.951 to 0.766 and marker RM336 was found to be the most appropriate marker to discriminate among the rice genotypes owing to the highest PIC value of 0.951. The allele frequency ranged from 37.35% (RM262) to 10.84% (RM585, RM336) with an average of 18.47%. The genotypes G82, G77, G68, G50, and G1; G65, G37, and G10; G71 and G11; G25 and G14; G39 and G27 have 100% genetic similarity according to the pair wise genetic similarity indexes. Genotype G10 had the least similarity (0.44 percent) to genotype G9, G16 with G17, G22 with G29, G28 with G30, and so on. The dendrogram based on UPGMA and Nei’s genetic distance classified the 83 rice landraces into 5 clusters with a similarity coefficient of 0.6 Cluster 2 had maximum thirty-two genotypes followed by cluster 4. The landraces that were derivatives of genetically similar types were clustered together on the dendrogram. These landraces is showed wide genetic divergence among the constituent in it and in future it will be useful for hybridization programme in plant breeding. SAARC J. Agric., 19(2): 13-25 (2021)

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, to explore the growth and yield performance of boro rice cv. BRRI dhan28 is influenced by foliar spray of potassium nitrate (KNO3) at four rice growth stages. The experiment consisted of four doses of KNO3 viz. 0 (Control), 0.25, 0.50 and 1.00 kg ha−1 and applied at four growth stages of rice development viz. at panicle initiation, at ear emergence, at anthesis period and at dough stage. This experiment was carried out in Randomized Complete Block Design (RCBD) with three replications with 10 m2 (4.0 m × 2.5 m) unit plot size and spacing between blocks and unit plots was 1 m and 0.5 m, respectively. Results revealed that foliar application of potassium nitrate at four growth stages significantly affected yield and yield contributing characters of BRRI dhan28. But most of the yield contributing characters did not differ significantly due to the interaction between potassium nitrate and stage of foliar spray. However, the foliar application of KNO3 @ 0.25 kg ha−1 showed the highest yield production (5.86 kg ha−1) while the lowest yield (4.85 kg ha−1) was found in control. Furthermore, better yield performances were recorded when the KNO3 was applied at panicle initiation stage rather than the other four growth stages. The total number of tillers, 1000–grain weight and grain yield, was higher with foliar spraying of a 0.25 kg ha−1 KNO3 at panicle initiation stage. From this experiment, it may be concluded that foliar application of KNO3 affected the yield performances of BRRI dhan28 and 0.25 kg ha−1 KNO3 produced the highest grain yield when applied at panicle initiation stage of boro rice.