Genetic variability, correlated response and path analysis of yield and yield contributing traits of spring wheat

Twenty spring wheat varieties were studied to find out genetic variability and genetic association for grain yield and its component characters. Both genotypic and phenotypic variances were highly significant in all the traits with little higher phenotypic variations as usual. Similarly, the low differences between the phenotypic and genotypic coefficients of variations indicated low environmental influences on the expression of these characters. High heritability coupled with high genetic advance were obtained with plant height, grains per spike, 100-grain weight, harvest index and grain yield. Genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients in most of the traits. Spikes per plant, grains per spike, spike length, 100-grain weight and harvest index were the most important characters which possessed positive association with grain yield. Path coefficient analysis revealed that among the different yield contributing characters spike per plant, grains per spike, 100-grain weight and harvest index influenced grain yield per plant directly. The direct effects of these characters on grain yield were positive and considerably high. Moreover, harvest index, days to maturity and spikes per plant had positive and higher indirect effect on grain yield through grains per spike. Thus selection for yield in spring wheat through these characters would be effective

Study on relationship and selection index for yield and yield contributing characters in spring wheat

The present study was conducted with twenty bread wheat genotypes at the experimental field of Bangladesh Agricultural University (BAU), Mymensingh, during the period from November 2008 to March 2009 to assess the relationship and selection index among yield and important yield attributing characters. Days to maturity, grains per spike, 100-grain weight and harvest index showed significant and positive correlation with grain yield per plant. Path coefficient analysis suggested that grains per spike followed by 100-grain weight and effective tillers per plant contributed maximum to grain yield positively and directly. Thus, selection based on these characters might be effective for improving grain yield. Selection indices were constructed through the discriminate functions using eight characters. From the results, the highest relative efficiency was observed with the selection index based on three characters; plant height and grains per spike and grain yield per plant. The present investigation indicates that the index selection based on these three characters might be more effective and efficient for selecting high yielding wheat genotypes

GENETIC DIVERGENCE OF JESSO-BALAM RICE (Oryza sativa L.) OF BANGLADESH

In total 27 genotypes of Jesso-Balam pure line rice germplasm were studied for fourteen morpho-physiological and four physico-chemical characters at Bangladesh Rice Research Institute, during T. Aman 2009 and T. Aman 2011 seasons. According to principal component scores, the two-dimensional scatter diagram (Z1-Z2) has apparently distributed the genotypes into seven clusters. According to Mahalanobis’ D2 statistic for the studied characters, the genotypes were clubbed into seven groups. The highest number of genotypes (6) were included in clusters I and III and the lowest two (2) in cluster V and VII. It was also revealed that no duplicate was existed among the genotypes. The intra-cluster distance was maximum (0.77) in cluster III and minimum (0.28) in cluster VII, while the maximum intercluster distance (28.37) was observed between the clusters III and IV and the minimum (2.49) between the clusters I and VII. The cluster V has produced the highest means for plant height (148.18 cm), straw yield per hill (39.97 g), panicle length (28.14 cm) and protein content (9.61%). But, the cluster IV has showed the highest means for seedling height (69.5 cm), flag and penultimate leaf area (1059.5 cm2), culm diameter (5.8 cm), filled grain number per panicle (3.64), grain length (8.63 mm) and 1000-grain weight (21.78 g), while the cluster VII had the highest means for grain yield per hill (31.27 g) and effective tiller number per hill (13.5) and the lowest mean for days to maturity (144). Therefore, the genotypes of cluster V need to be crossed with the genotypes of cluster IV or cluster VII, for developing new Balam rice with maximum other good characters. Finally, it could be concluded that the studied Jesso-Balam pure lines germplasm is a good source of valuable genes

Performance and variability for yield and yield contributing characters in spring wheat

The present study was conducted with twenty bread wheat genotypes at the experimental field of Bangladesh Agricultural University (BAU), Mymensingh, during the period from November 2008 to March 2009 to assess performance of the genotypes, variability, heritability and genetic advance among yield and important yield contributing characters. Considering yield per plant the genotype Peacock was the best followed by BAW-1008, Pavon-76, Mayoor, Bulbul and BAW-1004. BAW-1008 was the early maturing genotype followed by Mayoor, BAW- 861, BAW-1004 and Balaka. BAW-970, Akbar, BAW-1004, Pavon-76, BAW-861 and BAW-1006 were semi dwarf in plant height as such they were of desired type. TP-1 and Mayoor were superior for effective tillers per plant. BAW- 1004 was the best genotype for spike length and grains per spike. For 100-grain weight Bulbul, for harvest index BAW-1006 was the best. Days to 90% maturity, plant height, grains per spike, 100-grain weight and harvest index exhibited high heritability. Among them grains per spike, 100-grain weight and harvest index showed high genetic advance in percentage of mean

Haplotype Diversity at Sub1 Locus and Allelic Distribution Among Rice Varieties of Tide and Flood Prone Areas of South-East Asia

Single nucleotide polymorphisms and restriction digestion-based haplotype variations among 160 flood prone rice varieties were analyzed with enzymes Alu I and Cac8 I to generate polymorphisms at Sub1A and Sub1C loci (conferring submergence tolerance), respectively. Haplotype associated with phenotype was used to study the haplotype variations at Sub1A and Sub1C loci and to determine their functional influence on submergence tolerance and stem elongation. Three patterns at Sub1A locus, Sub1A0 (null allele), Sub1A1 (does not cut) and Sub1A2 (one SNP), and four patterns at Sub1C locus, Sub1C1, Sub1C2, Sub1C3 and Sub1C4, were generated. Both tolerant Sub1A1 and intolerant Sub1A2 had the same length, but the difference was presence of a restriction site in the Sub1A2, but absent at the Sub1A1. Further, two types of polymorphism were detected at the Sub1C, one included major length polymorphisms (165, 170 and 175 bp) and the other was a single restriction site at different position. Eight haplotypes (different combinations of the two loci), A1C1, A1C2, A1C4, A2C2, A2C4, A0C2, A0C3 and A0C4, were detected among 160 varieties. Haplotype A1C1 was comparatively more related to haplotypes A1C2 and A1C4, having the same Sub1A allele, and these haplotypes were found only in Bangladeshi, Sri Lankan and Indian varieties. Most tolerant varieties in A1C1 haplotype showed slow elongation, having tolerant specific Sub1A1 and Sub1C1 alleles. Further, the varieties Madabaru and Kottamali (A2C2) also showed moderate level of tolerance without Sub1A1 allele. These varieties were different with FR13A and also suspected to carry different novel tolerant genes at other loci. These materials could be used for hybridization with Sub1 varieties for pyramiding additional tolerant specific alleles into a single genotype for improving submergence tolerance in rice

Improving manual vacuum aspiration service delivery, introducing misoprostol for cases of incomplete abortion, and strengthening postabortion contraception in Bangladesh

AbstractThe Obstetrical and Gynaecological Society of Bangladesh was an important advocate in mobilizing government authorities to adopt new techniques for postabortion care and provide long-acting contraceptives post abortion. With the support of the International Federation of Gynecology and Obstetrics (FIGO), the Society provided commodities and training to increase the use of these techniques in 7 private and public hospitals and clinics. Data from two of these institutes for the January 2012 to June 2013 period showed a rapid decrease in the use of dilation and curettage, an increase in the use of manual vacuum aspiration (MVA) and misoprostol, and the progressive adoption of long-acting reversible contraceptives, permanent contraception, and injectable contraceptives in one of these two hospitals. The Directorates General of Health and Family Planning incorporated training in the use of MVA and misoprostol in their national operation plans. The success in these hospitals shows that the proposed changes have been well accepted by providers and clients