Study of heterosis in heat tolerant tomato (Solanum lycopersicum) during summer

Abstract

An experiment was conducted at the Vegetable Research Field of Olericulture Division, Horticulture Research Cente, Bangladesh Agricultural Research Institute (BARI), Gazipur during May to October 2008 to study heterosis using eight parents viz., P₁, P₂, P₃, P₄, P₅, P₆, P₇, and P₈. Most of the combinations showed better parent heterosis for earliness. Eight crosses showed positive heterosis for flower production. The highest heterotic effect for fruit set (%) was found in the cross P₆ × P₇ (62.59%) followed by that in P₇ × P₈ (60.49%) and P₁ × P₇ (40.00%). For fruits per plant, 8 crosses provided more than 15 % heterosis over better parent. Considering fruit yield per plant, higher degree of heterosis was manifested by 24 hybrids over better parent ranging from 13.58 to 282.63 %. Cross combination P₄ x P₇ showed the maximum significant positive heterosis followed by P₆ x P₇ (187.84 %), P₄ x P₈ (166.97 %), P₃ x P₇ (146.08 %), P₃ xP₆ (103.92 %), and P₁ X P₇ (100.45 %) and the minimum in P₄ x P₆ (13.58 %). For viable pollens, P₃ x P₅ (20.56 %) exhibited the highest positive heterosis. In case of shelf life, the highest heterosis was observed by the cross P₃ x P₆ (22.78 %) followed by that in P₄ x P₆ (22.29 %) and P₂ x P₆ (14.40 %). For fruit flesh thickness, 12 hybrids exhibited more than 10 % heterosis. Pollen tubes as well as viable pollens showed positive correlation with fruit set.

DOI: http://dx.doi.org/10.3329/bjar.v38i3.16980

Bangladesh J. Agril. Res. 38(3): 531-544, September 2013