Determining genetic diversity of deshi jute (Corchorus capsularis) for the improvement of fibre yield and associated traits

Commercially important natural fibres considered as fiber of the future are cultivated in different south-east Asian countries including India and Bangladesh. Unfortunately, they are characterized by limited genetic variation in terms of yield, quality and susceptibility to diseases and pests. Therefore, genetic deviation studies are crucial to develop a successful cultivation program to develop varieties to meet the growing demand for domestic and foreign jute products. This was conducted at the Central Jute Research Experiment Station of Bangladesh Jute Research Institute (BJRI), during Kharif seasons of 2014. 44 Thirteen progenies (1546, 1548, 4311, 4328, 4330, 4337, 4339, 5007, 6702/A, 6702/B, 6772, 6787, 6790) and two check varieties CVL-1 and CVE-3 (developed from Bangladesh Jute Research Institute) were investigated to study the genetic variability, genetic diversity and degree of association of different component characters related to fiber yield. The seeds of experimental plant materials were grown in Randomized Complete Block Design with three replications. Statistical analysis was run to find out the genotypic and phenotypic variances, correlations and cluster analysis for fibre yield related traits namely plant height (m), base diameter (cm), stick weight (g), fiber weight (g). Highly significant differences were observed among the genotypes for all the characters. Cluster analysis divided the accessions and varieties into four cluster. From our evaluation it was revealed that the treatment number 4337/06, 4339/06 and 6702/A performed better in most of the cases than the control varieties CVL-1 and CVE-3. These accessions may be used as parents for future variety development program.

INTRODUCTION quality textiles as well as a renewable source of biofuels [10]. Jute fibers characteristically show high gloss, good moisture absorption performance, rapid dehydration capacity and easy degradation [11]. Unlike heavy cotton requirements, jute is a rain-fed product that needs little fertilizer or insecticide. Production mainly concentrates in Bangladesh and India, almost 85% of world jute farming in this area (www.jutecomm.gov.in. 2014). Total global jute production is 339.3 million tons and only Bangladesh produced 145.2 million tons and represents 41.9% of the total [12]. In Bangladesh, 737,770 hectares of hectares are grown for jute, and the yield per hectare is 11,178 bales, and the total production is 8246797 bales [13].
Bangladesh is the homeland of quality jute production. Once upon a time it was the principle exporting goods of Bangladesh. Most of foreign currency was earned from this sector before liberation and it was sold as raw and finished goods. Not only its golden color but also its currency earning gives it the name Golden Fibre. Then, due to several factors including increased use of artificial fibres and low jute prices farmers found less incentive to grow jute. Many jute mills were forced to close, with jute production on the verge of extinction. At present, Bangladesh is trying to decrease this lack of demand to a huge extent by imposing the mandatory Jute Packaging Act, 2010 on a wide array of products, recently including 12 new products along with the six existing ones (Source: The Independent, Feb 11, 2014). According to the jute department, one bale of jute produces around 238 pieces of jute sacks, each of which holds around 50 kg of any item. So, it can be assumed that this will increase the domestic demand for jute bales by around 1.23 million and of jute sacks by around 300 million. An immediate amicable solution is needed to enlarge the export jute market of Bangladesh. The country has yet to tap the market of jute composites which is globally flourishing (US$6.5 billion by 2021) (The Financial Express 3 May, 2017).
Bangladesh Jute Research Institute (BJRI) has established a gene bank in 1982 now having world's largest collection of about 6060 accession of jute and allied fiber (JAF) germplasm from home and abroad [14]. Since jute is a largely self-pollinated product, its natural genetic variations are very limited, making it difficult for growers to develop new varieties of this crop through traditional breeding. The presence of genetic variation in a group of genes is the main problem of an improvement program. Assessment of genetic variation using appropriate parameters such as genotypic coefficient of variation, heredity and genetic progression is essential for starting an effective breeding program. In addition, heredity knowledge is crucial for selection-based improvement, as it shows the degree of transferability of a character to future generations [15]. Genetic progress provides information about the expected genetic gain from the selection of superior individuals [16]. High inheritance and high genetic development estimates are more useful than prediction of inheritance alone to predict earnings under selection [17].
Genetic diversity is a key factor in the effective selection of parents for the diversity development program. Genetic diversity can be investigated by morphological and reproductive functions. The diversity study in specimen collection is crucial for the identification of new genes and further development of bacterial plasma [18]. So, in order to develop high yielding varieties coupled with quality fibre, early maturity, wide adaptability, disease and pest tolerance, the promising varieties/ lines were crossed in all possible combinations to complete the 10 x 10 parents diallel set during 1999-2000. Their F 2 and subsequent generations were raised for selection superior lines/ plants according to desirable traits. Objective of this experiment was to develop high yielding lines by field evaluation of 13 promising lines with the studies and selection of desirable progenies.

MATERIALS AND METHODS
The experiment was carried out at the Jute Agricultural Experiment Station of Bangladesh Jute Research Institute (BJRI), Jagir, Manikgonj during the period from April to August, 2014.

Experimental Site
The experimental site was situated at 230 53.95" N latitude and 90004" E longitude with an elevation of 8.8 m from the sea level.

Climate and Soil
The experimental site was situated in the tropical climate zone, characterized by heavy rainfall during the month from May to September and scantly rainfall during rest of the year. The soil of the experimental field was sandy loam in texture having pH around 6.5 to 7.5. It belongs to the young Brahmaputra and Jamwia Floodplain Agro Ecological Zone. The land was medium high with uniform topography and almost homogenous with respect to soil fertilizer.

Experimental Material
The material comprised of thirteen progenies of white jute (C. cupsularis) including two check varieties CVL-1 and CVE-3. The genetically pure and physically healthy seeds of these genotypes were collected from the gene bank of Bangladesh Jute Research Institute (BJRI). Dhaka. Detailed of 13 progenies with two check varieties is given in Table1.

Design and Layout
The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Each plot had a single row of 3.6 m length. Space between rows was 0.30 m and block to block distance was 1.0 m. The genotypes were randomly distributed to each row with in each block.

Harvesting
These genotypes were harvested within 110 days after planting, just before pods develop. Selected plants (1.5-4.0 m tall) were pulled from soil with roots, washed and tied in bundles with a tag. Harvesting was done during the cooler time of day, such as early morning or late afternoon, and kept in cool and shaded place.

Data Analysis
Analysis of variance and covariance were done according to Aljibouri, et al., (1998) [19]. Coefficient of variation (PCV and GCV) and heritability (H2b) were calculated by the formulae suggested by Burton (1952) [20] and Hanson et al., (1956) [21], respectively. Genetic advance (GA) was derived by the formula given by Johnson, et al., (1955) [22]. A cluster diagram was drawn according to Singh and Chaudhury (1985) [23] that gave a brief idea of the pattern of diversity among the genotypes included in a cluster.

RESULTS
Observations were recorded from ten plants selected randomly ftom each replication for the four fibre yield related traits namely plant height (m), base diameter (mm), fibre weight/ plant (g), stick weight/ plant (g). Simple correlation coefficients were obtained between all possible combinations of characters related to fibre yield. Fibre yield was considered as the resultant (dependent) variable.
A total of 15 accessions and varieties were collected from Bangladesh Jute Research Institute (BJRI), were phenotypically evaluated for fibre yield and other Attributing Traits.
The analysis of variance (ANOVA) showed that the accessions had significant or very significant differences for all the studied characteristics, viz., plant height (m), base diameter (mm), fibre weight/ plant (g), stick weight/ plant (g). ( Table 2).
The mean performance of four important yield attributing character of 13 advanced lines with two check varieties are represented in the table 3.
From the investigation, we have found that genotypes ranged from 2.50 to 3.12 m for plant height (Table 3). Treatment 6787/07 gave highest plant height of 3.12 m, which was followed by 4330/08 that produced 2.96 m. The lowest plant height was given by the treatment 4328/06. While two check varieties, CVL-1 and CVE-3 heighted 2.73 and 2.68 respectively. The check variety CVL-1 produced highest base diameter of 20.32 mm, which was then followed by the treatment 6702/A and 6772/07 having 20.31 and 20.26 mm of base diameter respectively. Among them the treatments 4337/06 and 4339/06 gave better stick weight/plant than that of the check varieties. The highest stick weight/plant was produced 21.12 and 20.23g respectively. . In case of fibre yield/plant, the treatment 4337/06 produced highest yield of 9.89g. Which was followed by, 4339/06 and 6702/A having fibre weight/plant of 9.70 and 9.21g respectively. Contrariwise, the two check varieties, CVL-1 and CVE-3 gave 8.80 and 8.78 g fibre weight/plant. Similar findings was observed by Arju Miah., et al 2020 [24].
The ratios of Variability, heritability (h2b), genetic advance (GA) and GA in percent of mean for four yield and its related characters are shown in Table 4. The phenotypic variance appeared to be higher than the genotypic variance suggested considerable influence of environment on the expression of the genes controlling these traits. The greater percentage of PCV than GCV indicates the presence of considerable variability    [22] suggested that heritability and genetic advance should always be considered jointly during selection of a suitable line or progeny. The GCV and PCV were found to differ significantly for all the fibre yield components and biotic stress factors, which indicated a major role played by the environment in the expression of these characters. This is in agreement with the findings of Sawarkar et. al. (2014) [26].
Simple correlation coefficients between different pairs of characters are presented in Table 5. From the study, we have found that stick weight was positively and significantly correlated with fibre weight.
Cluster analysis was performed using ward's method. The euclidean distance was calculated based on morphological data and a UPGMA dendrogram was produced using the dissimilarity matrix for 15 jute accessions and varieties ( Figure 1). Cluster analysis based on morphological traits provides four clusters (Table 6). Clustering pattern showed that cluster II is composed of the highest number of accessions (6), while the other clusters consist of three genotypes each. Cluster III represented highest values of fibre weight/ plant (g) and stick weight/ plant (g). Highest mean of plant height (m) and base diameter (mm) was presented by cluster II and IV respectively (  [28], in tossa jute genotypes. A comparison between cluster means for different traits and relative contribution of the different traits to the total divergence revealed that the accessions with the desirable traits (highest mean values) were distributed into different clusters. Thus from the cluster analysis the treatments 4337/06, 4339/06 and 6702/A were found to be distinct with the desirable characteristics and may be incorporated in breeding programs to improve fibre yield and quality of jute.

DISCUSSIONS
Recently there are signs of jute regaining its economic importance. With the current consumer demand for reduction of the hazardous health and environmental effects of synthetics, there is increasing demand for the use of traditional jute goods, as well as jute in other diversified forms. Natural jute fibres are being substituted increasingly in a range of industries, including paper, celluloid products, non-woven textiles, composites (pseudo-wood), and geotextiles. Geotextiles for example are lightly woven fabrics used to prevent soil erosion, for seed protection, weed control and other agricultural and landscaping purposes. The biodegradable nature of jute is very well suited to this. It is also used to produce climate neutral bags; bags which are committed to reduce CO 2 . The cellulose in the jute plant produced from the inner woody core or parenchyma of the jute stem could also be used as an effective wood substitute. The recent development of the use of jute in car manufacturing in the automobile industry is example of the kind of huge potential future opportunities there are for use of jute (www.jute.org).
The available variability in a population can be partitioned into genetic parameters such as coefficients of variation of genotypic and phenotypic, heritability and genetic advance to serve as basis for selection of desirable genotypes in a breeding program. From our study, we have found yield attributing characters varies

CONCLUSION
Having a good selection of traits for selecting the desired genotypes within the planned breeding program, knowledge of the nature and degree of variation in available breeding material, the component properties' relationship to fiber performance and contribution, and their direct and indirect effects are very important.
The present study was visualized to divulge the nature and magnitude of genetic variability, the pattern of character association among the characters, the direct and indirect effects of component characters towards fiber yield and the degree of genetic divergence in germplasm accessions of deshi jute. The material for the present study comprised of thirteen progenies of jute (Corchorus capsularis L.) collected from BJRI, were evaluated using RCBD design for different quantitative characters. The analysis of variance showed significant differences among the genotypes for almost all the characters and from our study, we can insist that treatment number 4337/06, 6702/A and 4339/06 were found to be distinct with the desirable characteristics and may be incorporated in breeding programs to improve fibre yield and quality of jute.