Abstract
A study on the morphological and molecular characterization of chilli (Capsicum spp.) germplasm was conducted at the central research farm of Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur during the period from February 2015 to November, 2016. The study includes characterization of chilli germplasm based on morphological traits, estimation of genetic diversity among the germplasm by using SSR markers and also estimation of capsaicin and vitamin C. For morphological characterization, a total of thirty five germplasms from exotic and indigenous sources were studied for both Rabi and Kharif season in two consecutive years under field condition with BARI chilli-2 as check. All the germplasms were characterized for eighteen parameters from plant growth to yield traits. For Rabi season among the germplasms, the highest yield was recorded from the germplasm CO631 and it was 23.88 tha1 followed by CO635 (19.21 t ha-1) respectively. Whereas yield was significantly lowest for the germplasm CO648 and it was 2.99 t ha1. Similar trend was observed for the highest yield in the Kharif season recorded 23.04 t ha-1 (CO631), followed by CO525-1 (18.125 t ha-1) CO525 (17.69 t ha-1 and CO640 (17.50 t ha-1), respectively. Significantly, the lowest yield for kharif season was recorded from the germplasm CO002 (4.65 t ha-1) followed by CO648 (4.80 t ha-1). All other parameters were significantly different from each other both for Rabi and Kharif season. Forty chilli germplasms were analyzed using eight SSR primers. The SSR primers produced 30 SSR loci with an average value of 3.75 alleles per SSR locus. The similarity index matrix ranged from 0.0 to 2.74. Polymorphic information content (PIC) values of the SSR primers ranged from 0.543 to 0.735 with an average value of 0.658. The highest number of allele (5) was observed in primer CAMS- 647, whereas three primers CAMS-864, CAMS-880 and CAMS-885 showed lowest number of allele (3). The smallest allele was found for CAMS-236 (176 bp) and the longest allele was detected by the primer CAMS-864 (288 bp). Based on similarity matrix using the unweighted Pair Group Method of Arithmetic Means (UPGMA) dendrogram, chilli germplasms were grouped into four main clusters. SSR markers showed genetic variability in the studied chilli germplasm. Among the thirty six germplasm, for intra- day reproducibility capsaicinoides content was highest (2720 mg kg-1) in CO646 followed by CO610 (2628 mg kg-1), CO611-1 (2622 mg kg-1), BARI chilli-2 (2619 mg kg-1) and CO648 (2601 mg kg-1) respectively and the lowest (1191 mg kg-1) was recorded from CO638. In case of intra-day repeatability highest capsaicinoides content was recorded (2626 mg kg-1) from the germplasm CO611-1 followed by CO646 (2614 mg kg-1) and CO610 (2601 mg kg-1) respectively, whereas the lowest content of capsaicinoides (791 mg kg-1) recorded from the germplasm CO640. All the thirty six germplasms were analyzed for vitamin C content by UFLC method. Among the germplasms, vitamin C content was the highest 166.27 mg/100g (CO631) followed by CO635 (154.33 mg/ 100g), CO638 (143.27 mg/ 100g) and CO642 (140.77 mg/ 100g) respectively, whereas the lowest (65.10 mg/100g) content of vitamin C was recorded from the germplasm CO002.