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