One of the serious drawbacks in the successful development of bacterial wilt resistance tomato varieties has been the small fruited habit in many sources of bacterial wilt resistance. Large fruit size has been reported to be the most elusive character in bacterial wilt resistance breeding in tomato (Acosta et al., 1964; Sunarjono, 1980).
Ten plants each of the resistant (CL 32d-0-1-1-1-1-19 GS) and susceptible varieties (Pusa Ruby) were evaluated for locules/fruit. Those falling under two groups (viz. locule number < /= 3 and >3) in the two genotypes were analyzed for their association with resistance to bacterial wilt using multinomial probability tests (Table 1).
Table 1. Contingency table for testing association between locules/fruit and resistance to bacterial wilt.
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Disease reaction Locules/fruit Total
< /= 3 > 3
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Resistant 4 6 10
Susceptible 1 9 10
Total 5 15 20
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The probability of association of fewer locules (< /= 3) per fruit and
resistance to bacterial wilt was only 0.15. This suggests independent
genetic control of locules/fruit and bacterial wilt resistances.References:
Acosta, J.C., J.C. Gilbert and V.L. Quinon.1964. Heritability of bacterial wilt resistance in tomato. Proc. Amer. Soc. Hort. Sci. 84:455-462.
Sunarjono, H. 1980. Increasing tomato production, disease resistant varieties show promise. Indonesian Agric. Res. Develop. J. 2:5-7.