SCREENING OF TOMATO (Lycopersicon esculentum L.) GENOTYPES FOR SALT TOLERANCE DURING EMERGENCE

Abstract

Seed emergence and seedling establishment of tomato genotypes are severely affected by saline conditions. Hybrid tomato cultivars could be adaptable in salt stress condition. For this reason, an invitro experiment was conducted at the laboratory of department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur, Bangladesh, during the period of October 2015 in rabi season to screen out the tomato genotypes for salt tolerance during emergence. Ten tomato genotypes namely BARI Tomato-2, BARI Tomato-3, BARI Tomato-5, BARI Tomato-11, BARI Tomato-14, BARI Tomato-16, Mintoo, Unnoyon, Mintoo Super and Sawsan were germinated in plastic pot on sand bed irrigated with five levels of salinity treatment i.e. 0, 4,8,12 and 16 dSm-1 . The two factorial experiment was laid out in completely randomized design (CRD) with three replications. Data were collected on days to first emergence, days to 50% emergence, emergence percentage, radicle length, plumule length, radicle fresh weight, plumule fresh weight, radicle dry weight, plumule dry weight, ratio on radicle and plumule fresh weight, ratio on radicle and plumule dry weight, proline content, K + /Na+ , Seedling Vigor Index and Salt Tolerance Index were recorded at 14th days after sowing of seeds in plastic pots. The emergence parameters like days to first emergence, days to 50% emergence, emergence percentage was maximum in Unnoyon genotype in all the treatments which germinated earlier (3 to 10 DAS) and performed maximum emergence percentage (100%) than other genotypes. BARI Tomato-3 showed minimum value in most of the cases. Seedling parameters like radicle length, plumule length, plumule fresh weight, radicle fresh weight, plumule dry weight, radicle dry weight, ratio on radicle and plumule fresh weight, ratio on radicle and plumule dry weight, Seedling Vigor Index, Na+ /K+ , proline content and Salt Tolerance Index was highest in BARI Tomato-2, Mintoo and Unnoyon in contrast the lowest performance of these traits were revealed in BARI Tomato-16 and BARI Tomato-3 at higher salinity treatment (12 and 16 dSm-1 ) than other genotypes in most of the cases. Overall results of the experiment exhibited BARI Tomato-2, Mintoo and Unnoyon found to be the more tolerant genotypes at higher salinity stress in respect of seed emergence and seedling characters than other genotypes have studied in this experiment.