Natural incidence of chromosomal chimerism and interchanges in Trichosanthes cucumerina Var. Anguina and its Impact on fruit set Bano Mehnaz, Sharma Geeta1* 1Department of Botany, University of Jammu, Jammu-180 006 Department of Botany, G.G.M. Science College, Jammu *Email geetaji@yahoo.com
Online published on 5 October, 2021. Abstract Morpho-cytological tools carry great importance for identifying agronomically valuable and cytologically stable cultivars of vegetable crops like Trichosanthes cucumerina var. anguina (snake gourd). Presently, two cultivars of this cucurbit, one commercial and another locally grown in Jammu district, have been examined for phenotypic aspects. These correspond in most of foliar and floral attributes except for the yield, which is quite high for local cultivar but very low for commercial one. To identify bottlenecks accounting for limited fruit production in commercial cultivar, its six plants along with seven individuals of local form have been analysed for reduction division in male track. While pollen mother cells (PMCs) of local cultivar consistently contain 22 chromosomes showing regular behavior, commercial form has 7.2% hypo-/hyperploid cells (2x±2 chromosomes), with the remaining cells being diploid. Later cultivar is further unusual in having quadrivalents/trivalents in 8.6% eu-and 30% hyperploid cells as well as irregular segregant patterns of 15: 7, 13: 9, 12: 10, 10: 3: 9 and 11: 1: 10 type in 24% cells. These anomalies seem to have accounted for reduction in its pollen viability to 71.63%. In spite of having three-fourth fertile pollens, highly reduced fruit (10–15 per vine) and seed set (20–22 per fruit) in our commercial cultivar indicates that somewhat similar aberrations may be present in female tract. Apart from describing meiotic anomalies present, adverse impact of these on reproductive capacity of a diploid snake gourd cultivar has been discussed in this communication. Top Keywords Aneuploids, Quadrivalents, Snake gourd, Trichosanthes cucumerina var. anguina, Yield. Top |