Genetic variability analysis for different agro-morphological characters of tossa jute

ABSTRACT

The experiment was conducted with tossa jute (Corchorus olitorius L.) at Jute Agricultural Experimental Station, Jagir, Manikgonj during 2017. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Significant variations were observed for different agro-morphological characters among the genotypes. Phenotypic coefficient of variation (PCV) was higher than corresponding genotypic coefficient of variation (GCV). The highest PCV was observed for the character green wt. with leaves (22.94). Heritability was highest for green bark thickness (98%) followed by green wt. without leaves (93%), base diameter (81%) and leaf length (79%). The highest genetic advance as percentage of mean (44.38%) was estimated against green weight without leaves, followed by (41.62%) was estimated against green bark thickness, (21.50%) was estimated against base diameter.

Key words: Genetic variability, heritability, genetic advance, tossa jute.

Genetic diversity analysis for different agro-morphological characters of tossa jute

ABSTRACT

The genetic diversity was studied for eleven growth and yield related characters in fifty three genotypes of tossa jute which were collected from the Gene Bank of Bangladesh Jute Research Institute (BJRI), Dhaka. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The highest intra-cluster distance was estimated for cluster IV (0.338) which consisted of fourteen genotypes followed by cluster III (0.330) for eighteen genotypes, cluster V (0.297for seven genotypes and cluster II (0.284) for eleven genotypes. Cluster III contained the largest number of genotypes (eighteen) followed by cluster IV (fourteen) and cluster II (eleven), respectively. The inter cluster distance was maximum between cluster I and V (20.616) followed by the distance between clusters I and IV (18.405), I and III (14.857), II and V (10.984), I and II (10.277) indicating that the genotypes grouped within these cluster were highly divergent from each other. The least genetic distance at inter-cluster level was observed between cluster IV and V (2.871), followed by the distance between clusters III and IV (4.296), and between II and III (4.584) indicating that the genotypes of these clusters were genetically closely related. The maximum contribution was paid by the character, base diameter (0.5335) followed by green wt. without leaves (0.4790), green bark thickness (0.4672) and plant height (0.3858).

Key words: Genetic diversity, clustering, tossa jute.

Introduction

 Information on genetic divergence among the parental materials is vital to plant breeder for an efficient choice of parents for hybridization. More diverse parents are the chances for high heterotic F1S and broad spectrum of variability in segregating generation (Murty and Arunachalam, 1966). However, evaluation of genetic diversity is important to know the source of gene for a particular trait within the available germplasm (Tomooka, 1991). In the past, very few researches have been carried out related to morpho–agronomic diversity and relationships in jute with diverse geographical origins. Plave and Sinha (2005) used 6 accessions of C. capsularis L. and 7 accessions of C. olitorius L. for their study. Recently, Benor et al. (2012) used only C. olitorius L. species to study genetic diversity and relationships inferred from molecular and morphological data. Moreover, multivariate methods particularly principal component analysis (PCA) have proven to be useful for characterizing, evaluating and classifying germplasm when a large number of accessions are assessed for several characteristics of agronomic importance (Badenes et al., 2000). Rapid genetic improvement of crop depends on the availability of sufficient genetic diversity, which could be selected and combined in various forms to produce reasonable improvement (Wani, 2011). Hence in the present study the genetic diversity was studied for eleven growth and yield related characters in fifty three genotypes for further development and creation of higher diversity in tossa jute.

Effect of different plant spacing along with concentrations of growth regulator (mepiquat chloride) and time of foliar application on seeds boll of cotton

ABSTRACT

Plant growth regulators (PGRs) are used in cotton production to optimize yield and quality and even suppressing excess growth whenever necessary. Experiments were conducted PGRs are used in cotton production to optimize yield and quality and even suppressing excess growth whenever necessary. Experiments were conducted in 2017 at Cotton Seed Multiplication, Training and Research Farm, Sreepur, Bangladesh to study the response of cotton yield and quality to different plant spacings, concentration and time of application of mepiquat chloride (MC) growth regulator. The maximum seeds boll-1 (119.61) was recorded at spacing 75 cm × 30 cm and lowest seeds boll-1 (116.92) was marked from spacing 45 × 30 cm. in respect of MC, the highest seeds boll-1 (122) was obtained from foliar sprayed at 3.0 ml L-1 water at 75 DAE and the lowest (109.33) was observed in 1.0 ml MC L-1 water at 25 DAE. Considering combined action, seeds boll-1 was marked highest (122.67) from 3 ml MC L-1 water at 75 DAE with 60 cm × 30 cm spacing and became lowest (106.42) at 1 ml MC L-1 water sprayed at 50 DAE with 45 cm × 30 cm spacing.  So, plant spacing of 60 cm x 30 cm can be practiced for profitable cotton production in Sreepur areas of Bangladesh.

Key words: Plant spacing, growth regulator, time of foliar, seed boll, cotton.

Molecular diversity assessment using ssr primers confirming distinct species of jute germplasm under Corchorus genus

ABSTRACT

The aim of the experiment was to find out genetic diversity of some jute germplasm collected from different locations of the world that are stored at the gene bank of Bangladesh Jute Research Institute (BJRI). The experiment was conducted at the laboratory of Cytogenetics department of Genetic Resources and Seed Division of BJRI. Genetic variation among 22 jute germplasm including 9 varieties of BJRI were determined using 33 SSR primers. DNA was extracted from seedlings following mini preparation CTAB method with some modifications. Vertical gel electrophoresis system was used with polyacrylamide gel. Among these,   14 primers were polymorphic and amplified 39 loci. The highest gene diversity value among the polymorphic primers was 0.685 and the lowest was 0.177 with an average of 0.507. The highest genetic distance value (1.0) was found between Corchorus capsularis (white jute) and C. olitorius (dark jute/tossa jute) germplasm. Among the C. olitorius germplasm, the highest genetic distance value (0.4) was found between accession no. 1039 and accession no. 1347. Among the C. capsularis germplasm, accession no. 4484 showed the highest genetic distance value (0.214) with varieties CVL-1 and BJRI Deshi Pat Shak-1. UPGMA dendrogram, based on genetic differences separated the germplasm of two different species in two main clusters and the cluster of C. olitorius is subdivided into two sub-clusters. We found no genetic similarity between the two species of jute. Plant breeders can consider the studied germplasm of C. olitorius as more potential for crossing programs as they have good genetic diversity.

Key words: Genetic polymorphism; Genetic variation; Jute; Molecular markers; SSR Markers; UPGMA dendrogram

Effect of plant spacing on the incidence of rice stem borer and gall midge in some rice varieties

ABSTRACT

Field experiments were conducted to find out the effect of spacing and variety on the incidence of major insect pests during the aman season. The plant spacing had no influence on the infestation of rice stem borer and gall midge in rice varieties. At maximum tillering stage significantly lowest rice stem borer and gall midge infestation was recorded in Binasail and BRRIdhan32; while the highest infestation was recorded in susceptible TNI by Binadhan-4 and BRRIdhan32, respectively.

Key words: Plant spacing, rice varieties, rice stem borer and gall midge

Assessment of variation among eleven kenaf germplasm using molecular markers

ABSTRACT

Genetic variation of 11 kenaf (Hibiscus cannabinus L.) germplasm was analyzed through SSR primers. Outof 25 primers 8 polymorphic primers were detected among the kenaf germplasm. A total of 22 alleles were detected in 11 kenaf germplasm. The highest number of alleles (4) was detected by marker JMBD2064. The highest level of gene diversity value (0.640) was observed for primer 2064. The study revealed that markers having the highest number of alleles showed higher gene diversity. The PIC values ranged from a low of 0.253 (JMBD880) to a high of 0.581 (JMBD2064). PIC values also showed a significant positive correlation with the number of alleles and allele size range for microsatellites. The highest genetic distance (0.857) was observed between the accessions 4626, 3827 and 4626, 5029. For dendrogram the Unweighted Pair Group Method with Arithmetic Means (UPGMA) cluster tree analysis led to the grouping of the 11 germplasm into three clusters. Cluster 1, 2, and 3 contain 5, 2 and 4 germplasm respectively. Overall, this study indicated that germplasm having the highest genetic variation can be used as parental source for improved breeding lines to develop kenaf varieties.

Key words: Kenaf, molecular marker, genetic variation

Introduction

Kenaf (Hibiscus cannabinus L.) is a fibre yielding crop cultivated as substitute of jute. It is a bast fibre crop like jute having versatile applications. In Bangladesh, the fibre from kenaf is primarily mixed with bast fibre obtained from jute for making bags, sacks, twines, ropes, cordages and carpets. Kenaf is rapidly replacing jute, because the crop has less labour requirements, is cheaper to produce, may be grown on a wide range of soils under varied climatic conditions, and is not necessarily competitive with food crops. Kenaf also produces more biomass in poor soil where even jute cannot be grown. Genetic variability is the pre-requisite for any plant breeding program. Wild, weedy, primitive cultivar, land races and advanced breeding lines of crops are the major components of genetic resources. There is a germplasm depository (Gene Bank) at Bangladesh Jute Research Institute (BJRI). Before these resources can be exploited, they should be systematically evaluated to assess genetic diversity. DNA fingerprinting is an important approach to identify duplicates in the germplasm collections. Core collection or a subset of germplasm that might comprise up to 10 percent of the total and represent genetic diversity of a large collection can be evaluated through molecular markers. Such well characterized collection would be easy to maintain and serve as asource of material for use in breeding programs for introducing desired variability to develop improved varieties of crop plants. With increasing production and utilization of kenaf breeding for desired agronomic traits such as high fiber yield and disease-resistance become important. There are many local varieties and germplasm of kenaf. Their qualitative traits need to be improved. Before hybridization, selection of parents is an important step. Morphological characters have provided very limited information for varietal identification of kenaf germplasm (Deng et al., 1994; Siepe et al., 1997; Cheng et al., 2002). This selection procedure can be practiced based on polymorphism in DNA level. Random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) have been developed (Zhang et al., 2013). The detection of polymorphism by DNA-based methods such as Random Amplification of Polymorphic DNA (RAPD) and microsatellite markers (SSR) is more accurate than morphological methods (Rajora and Rahman 2003). SSRs are the most important genetic markers for the analysis of genetic diversity, high