No abstract

Abscisic acid (ABA) is a phytohormone widely distributed among members of the land plant lineage (Embryophyta), regulating dormancy, stomata closure and tolerance to environmental stresses. In angiosperms (Magnoliophyta), ABA-induced gene expression is mediated by promoter elements such as the G-box-like ACGT-core motifs recognized by bZIP transcription factors. In contrast, the mode of regulation by ABA of gene expression in liverworts (Marchantiophyta), representing one of the earliest diverging land plant groups, has not been elucidated. In this study, we used promoters of the liverwort Marchantia polymorpha dehydrin and the wheat Em genes fused to the β-glucuronidase (GUS) reporter gene to investigate ABA-induced gene expression in liverworts. Transient assays of cultured cells of Marchantia indicated that ACGT-core motifs proximal to the transcription initiation site play a role in the ABA-induced gene expression. The RY sequence recognized by B3 transcriptional regulators was also shown to be responsible for the ABA-induced gene expression. In transgenic Marchantia plants, ABA treatment elicited an increase in GUS expression in young gemmalings, which was abolished by simultaneous disruption of the ACGT-core and RY elements. ABA-induced GUS expression was less obvious in mature thalli than in young gemmalings, associated with reductions in sensitivity to exogenous ABA during gametophyte growth. In contrast, lunularic acid, which had been suggested to function as an ABA-like substance, had no effect on GUS expression. The results demonstrate the presence of ABA-specific response mechanisms mediated by conserved cis-regulatory elements in liverworts, implying that the mechanisms had been acquired in the common ancestors of embryophytes.

Genetic diversity of 58 traditional local rice genotypes was studied under rainfed condition through Mahalanobis D 2 statistic for grain yield and yield contributing characters. The genotypes were grouped into nine clusters. The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the genotypes of different clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. The cluster III contained the highest number of genotypes (13) and the cluster I contained the lowest (2). The highest intra-cluster distance was noticed for the cluster I and the lowest for cluster VII. The highest inter-cluster distance was observed between cluster I and IV followed by cluster IX and IV, cluster I and VI and the lowest between cluster V and III. Regarding inter-cluster distance, the genotypes of cluster IV showed high genetic distance from all other clusters. The genotypes from cluster IV could be hybridized with the genotypes of other characters of other clusters for producing transgressive segregants. Based on positive value of vector 1 and vector 2, flag leaf length, plant height, panicle length and grain breath had maximum contribution towards genetic divergence. The highest cluster means for yield, 1000 grain weight and grain breath were obtained from cluster VIII. The highest plant height, flag leaf width and panicle length were found in cluster II while the lowest mean value for yield, days to flowering and maturity, unfilled grain and the highest mean value for grain length breadth ratio were found in cluster II. Therefore, more emphasis should be given on cluster IV and cluster VIII, cluster I and cluster IV for selecting genotypes as parents for crossing with the genotypes of cluster II which would be used to produce new recombinants with desired traits.

Fish pickle was developed from Thai pangus (Pangasianodon  hypophthalamus) fish muscle by using different types of food additives. Mustard oil and soybean oil were used for preparing fish pickle. Dorsal muscle and whole fish muscle without bone were used as raw material for preparing fish pickle. Changes in nutritional composition, pH, bacteriological and sensory attributes were determined at room temperature (30–35°C) according to standard procedures. At room temperature (30-35°C) fish pickle prepared from dorsal muscle and whole fish muscle using both mustard oil and soybean oil remained in acceptable condition until 12/13 days. Bad smell produced in the pickle after 15th day of storage. Moisture, protein, lipid and pH value decreased but ash content increased with the progress of storage period. In case of soybean oil used pickle deterioration was faster than the pickles prepared using mustard oil. Bacterial load was higher in soybean oil pickle and the pickle prepared from whole fish muscle. J. Bangladesh Agril. Univ. 16(3): 545–552, December 2018

An experiment was carried out to study the genetic components for eight panicle characters in rice using an 8-parent half diallel cross excluding reciprocals during Transplant Aman season, 2003. The parental genotypes used in the study were BRRI dhan29, BR4828-54-4-l-4-9, BRR1 dhan28, 1R8, Amol3, 1R65610-38-2-4-2-6-3, Minikit and ZhongYu7, which were chosen for their diversity in panicle characters. Hayman's analysis of variance (ANOVA) indicated importance of both additive and non-additive genetic components for all the panicle characters except dominance component for filled grains/secondary branches. The ANOVA showed unidirectional dominance for the characters viz, primary branch length, secondary branch length, primary branches/panicle, secondary branches/panicle and filled grains/primary branch, asymmetrical gene distribution for all the panicle traits except filled grains/secondary branch and residual dominance effects for all the panicle characters studied. Two out of eight panicle characters viz., primary branches/panicle and unfilled grains/ secondary branch followed the simple additive-dominance genetic model. The rest of the panicle characters showed nonallelic gene interaction or epistasis. According to Vr-Wr graph, partial dominance was involved in the action of genes governing the inheritance of primary branches/panicle, while complete dominance was involved in the inheritance of unfilled grains/secondary branch. Most of the dominant genes for primary branches/panicle belonged to other hand, 1R8 possessed most of the dominant genes, while 1R65610-38-2-4-2-6-3 possessed most of the recessive genes for unfilled grains/secondary branch. The estimates of components of variance demonstrated involvement of both additive and dominant components in the inheritance of primary branches/panicle and unfilled grains/secondary branch. The distribution of dominant and recessive genes was unequal in the parents for these two characters also. There was drastic influence of environment on these two panicle characters following simple additive-dominance genetic model. Heritability in narrow sense (h 2 ns) was very high for primary branches/panicle and unfilled grains/secondary branch.