Institutional Repository
Thesis Issued 2026-09-08 EN

Studies on genetic diversity and production technology of pointed gourd

Author: A. S. M. Mahbubur Rahman Khan
Groued

Abstract

Thirteen experiments were conducted to characterize and to standardize on production technology of pointed gourd (Trichosanthes dioica). The field experiments were conducted at the Regional Agricultural Research Station, BARI, Ishurdi, Pabna during the period from 2000 to 2003. Isozyme and RAPD studies were conducted at the laboratories of Bangladesh Agricultural Research Institute, Joydebpur, Gazipur and Bangladesh Agricultural University, Mymensingh during the period from 2002 to 2003. Morphological characters of 64 pointed gourd accessions were studied. Significant variations were recorded among the accessions in respect of plant, leaf, flower, fruit and seed characters. Based on multivariate analysis, the accessions of pointed gourd were grouped into 12 clusters. The cluster V had the highest number of accessions (9) followed by cluster 1 (8), X (7) and IX (7). The cluster II, III, and VIII had 3 accessions each and clusters VI had 2 accessions. The accessions collected from the same location were grouped into different cluster. Three isozymes viz. acid phosphatase, peroxidase and glutamate oxaloacetate transaminase were used to investigate the variability at genetic level. Eight acid phosphatase, 7 peroxidase and 9 glutamate oxaloacetate transminase electrophoretic zymotypes were formed by 19, 11 and 19 bands at different Rf values varying from 0.19 to 0.82, 0.38 to 0.69 and 0.15 to 0.95, respectively. Random Amplified Polymorphic DNA (RAPD) was used to study the genetic diversity of the pointed gourd accessions under study. Amplification with 5 decamer random primers generated 38 RAPD markers, of which 30 (79.95 %) were polymorphic. The UPGMA dendogram based on the Nei's genetic distances segregated the accessions into 12 clusters. Comparison between clustering on morphological and molecular parameters indicated that grouping of accessions based on morphological traits did not match with the grouping based on isozyme and RAPD markers. There was 66.54 and 52.4 % synchronization of cluster memberships in morphological and isozyme and morphological and RAPD data, respectively. Maximum yield and economic return was obtained when pointed gourd was grown from mother plant root and trained over bamboo pandal. The response of vine cutting to IBA for rooting was more pronounced than NAA irrespective of concentrations. Highest survivability was recorded in PG001 when treated with 50 ppm IBA. Runner vine cutting treated with 50 ppm IBA gave the highest survivability. Cuttings collected from the middle part of the vine with 3 nodes treated with 50 ppm IBA showed higher survivability percentage. PG025 bored highest yield when planted in October. The yield decreased with delay in planting irrespective of accession. Natural + hand pollination produced the highest fruit yield as well as economic return and was significantly superior to natural, hand and farmer's pollination methods. The highest yield and maximum economic return were recorded in crops receiving additional fertilizer and medium pruning. Among the four promising lines, PG025 provided the highest yield in all the locations viz. Ishurdi, Rangpur and Hathazari.