Implications of heterosis and combining ability among productive Single cross hybrids in tomato

Ten tomato commercial and productive single cross hybrids extensively grown in Northern Transitional Zone of Karnataka were planted in the field at UAS, Dharwad following RBD design with three replications. A 10 x 10 diallel set was generated by crossing these single cross hybrids in all possible combinations (excluding reciprocals) and 45 double cross hybrids were planted during February, 2007 with three replications with a view to estimate heterosis and combining ability to facilitate identification of heterosis combinations for all the ten characters studied. The range of heterosis (%) over mid parent and better parent was wide for number of clusters per plant and number of locules per fruits as compared to other characters. The number of significant heterosis hybrids in desirable direction for both mid parent (28 hybrids) and better parent( 24 hybrids) was highest for number of locules per fruit followed by number of cluster per plant (mid parent-17 hybrids, better parent-11 hybrids). The overall gca and sca status for SCH and DCH respectively revealed that among single cross hybrids JK-Desi was the best general combiner for yield and most of the traits followed by Pragathi and Maharani. Out of top five double cross hybrids, only two hybrids viz., JK-Desi x Sasya and JK-Desi x Shivaji expressed significant high positive heterosis over mid-parent and better parent along with better performance in term of yield per plant. It is noteworthy to mention that three of the five top double cross hybrids had JK-Desi as one of the common parent which is potential donor for yield per plant, number of fruits per plant, number of branch per plant, plant height and pericarp thickness.