Studies on the Extent of Genetic Contamination in Seed Production of Ridge Gourd (Luffa acutangula Roxb.)

Studies were conducted during 2002-2005 (Rabi season) to evaluate the extent of genetic contamination in round fruited ridge gourd (recessive) vehen grown for seed production under open field conditions. The round fruited ridge gourd was sown at 200 m, 400 m, 600 m and 800 m distance from Arlia Sumeet (long fruited) which acted as the local marker (dominant). The highest percentage of genetic contamination was recorded at a distance of 200 m from the contaminator (Arka Sumeet) (28.62% and 88.1%, respectively, in the years 2003 and 2005). It was also observed that there was a gradual reduction in contamination level with increasing distance from 28.62 to 17.44% at 600 m distance in 2003 and 88.11% at 800 m to 74.23% in 2005. The lowest percentage of contamination was recorded at the highest isolation distance (at 600 m, 17.44% in 2003 and at 800 m, 74.24% in 2005), although it is not within the prescribed maximum permissible limit of genetic contamination (1 and 2% for foundation and certified seed respectively). In the present study, in all the isolation distances studied, the level of contamination is well above the permissible minimum seed certification standards (99 and 98 % genetic purity for Foundation and Certified seed respectively). Hence, any reduction in the isolation distance from the prescribed (800 m) isolation would drastically affect the genetic purity of ridge gourd for seed production under open field conditions.