Physiological quality: the effect of different levels of seed vigour and waterlogging stress

Abstract

Soil flooding is considered one of the main abiotic stresses in several ecosystems, causing decreases in the genetic potential of plant growth and yield. The study was carried out with the aim of evaluating the agronomic traits of soybean cultivars, as well as the physiological quality of the seeds produced, as a function of the initial vigor of the seeds, of different cultivars, subjected to soil flooding stress at different phenological stages of the crop. . Soybean seeds with vigor variations obtained under controlled conditions, of the NA5909RG, NS6209RR, TMG7363RR and TECIRGA6070RR cultivars were used. The study consisted of three factors: four cultivars, two levels of seed vigor (high and low vigor), and three cultivation regimes (cultivation without flooding; cultivation with temporary flooding for 5 days from the V6 stage onwards; and cultivation with 5-day temporary flooding starting at stage R2). The agronomic traits were determined by evaluating the number of pods per plant, number of seeds per pod, number of seeds per plant, mass of a thousand seeds, plant height, number of productive nodes on the main stem, height of insertion of the first pod. , stem diameter, seed yield per plant, and centesimal protein and oil contents. Soil flooding stress causes reductions in the number of pods per plant, number of seeds per plant, number of productive nodes on the main stem, number of secondary branches, seed yield per plant, oil content, and physiological quality of the seeds produced. The high vigor of the seeds provides increments in the yield of seeds per plant, in the mass of a thousand seeds, in the number of nodes in the main stem, in the height of the insertion of the first pod, and in the oil content of the seeds.