Respostas fisiológicas e morfoagronômicas a estresse de calor e capacidade de combinação para aparência e rendimento de tubérculos de genótipos de batata

Abstract

Potato is a crop native to temperate regions, being sensitive to high temperatures during cultivation, which can reduce yield and quality. In the tropical growing areas of Brazil, some months of the year have high temperatures, which are unfavorable to cultivation. To assist in the development of new genotypes it is essential to understand how heat affects morphological, physiological and postharvest characters in the available germplasm. Moreover, to meet the demand for cultivars adapted to Brazilian growing conditions, the identification of genitors for the development of new varieties is fundamental. In this sense, three studies were developed. The first aimed to evaluate the performance of 65 potato genotypes regarding morphological and physiological responses in two different temperature conditions, the control, which had a temperature range of 13-25°C (30 days at planting) to 16-29°C (end of cycle), and the stress, with ranges 17- 29°C to 18-28°C. In this study, the genotypes showed variability in response to different temperature conditions. The temperature caused changes in the response of the genotypes to the physiological variables. Regarding the morphological variables, the genotypes that presented the best performance in the control also presented the best results under stress. The second study aimed to evaluate the same 65 genotypes with respect to post-harvest performance, analyzing the frying quality and storage of the tubers. The results suggest that the genotypes cultivated under stress showed better chip color scores and longer tuber dormancy periods, associated with shorter sprout lengths. The third study proposed to estimate the combining ability of potato genotypes for tuber appearance and yield characters. Eight families were evaluated in a partial diallel model (3x3). The additive gene effects predominated in the control of tuber appearance and yield characters.