QUALITY OF TOMATO SEEDS PRODUCED AT HIGH TEMPERATURE DURING DIFFERENT STAGES OF DEVELOPMENT

Abstract

There are few studies in tomato (Solanum lycopersicum L.) on the effect of high temperature during seed development. The objective of this research was to evaluate physical and physiological quality parameters of seeds from fruits developed at high temperature during different stages of development. The native variety Campeche 40 (C40), the variety Money Maker (MM) and the experimental line L52 were planted in the Spring 2020 using two sections of a greenhouse, one ventilated for the control treatment (CT, average maximum temperature AMT = 35.2 ºC) and the other one with heating for the high temperature treatment (HT, AMT = 38.6 ºC). The high temperature was applied at four stages of fruit development of the fourth cluster, T1: from anthesis, T2: 15 d after anthesis (DAA), T3: 30 DAA, T4: 45 DAA, up to maturity in each case. The average seed moisture content of all treatments was 7.2 %. Genotypes C40 and MM produced a higher (P ≤ 0.01) number of seeds per fruit (99) than L52 (53.3). One-thousand seed weight (SW) and seed length (SL) of MM were higher (2.97 g and 3.66 mm, respectively) than the rest. Seeds from C40 was more vigorous (germination of aged seed GEA = 99 % and root emergence rate of aged seed VEEA = 5.94 radicles d^-1). Control treatment (CT) produced seeds with higher SW and SL (2.95 g and 3.7 mm, respectively) but less vigorous. Seeds that at any stage of their development were affected by HT germinated better and faster after being subjected to the accelerated aging treatment. High temperature favored the physiological quality of seeds, but not the physical quality.