Genetic diversity and screening for bacterial wilt in tomato (Lycopersicon esculentum)

Abstract

Thirty-four tomato genotypes from different geographical locations were evaluated for genetic diversity and screened for bacterial wilt (BW) caused by Ralstonia solanacearum. Results revealed that plant height, fruits per cluster, fruit weight, fruit diameters, locules per fruit, fruit firmness, yield per plant, and quality parameters exhibited high heritability and genetic advance. Clustering based on D2 analysis, classified genotypes into four clusters. Maximum intra-cluster distance was recorded within cluster I and maximum inter-cluster distance between cluster II and IV followed by cluster I and IV, indicating existence of wide genetic variability. Genotypes in cluster IV (AVTO 1711, AVTO 1717 and AVTO 1718) recorded high fruit weight coupled with high yield. These may be explored as promising donors for developing large sized bacterial wilt resistant tomatoes. The large fruited genotypes in cluster IV can also contribute to the genetic improvement of existing bacterial wilt resistant varieties placed in cluster I. Out of 34 genotypes screened for BW disease, 5 genotypes were classified as resistant and 7 as moderately resistant.

Keywords

• Bacterial wilt
• genetic advance
• heritability
• humid tropics