Physiology and morphology of seedlings originating from seeds harvested in different thirds and cotton genotypes cultivated under the edaphoclimatic conditions of Uberlândia - MG

Cotton has great importance in Brazil. The percentage, speed and uniformity of seedling emergence depend on this potential. The objective of this work was to evaluate the physiological and morphological quality of seeds from different thirds of ten genotypes of white fiber cotton grown in the edaphoclimatic conditions of Uberlândia - MG. The experiment was conducted in the 2017/2018, in an area of 500m². Eight commercial genotypes (BRS 368RF, BRS 372, DP 1228 B2RF, FM 975 WS, FM 982, IMA 5675 B2RF, IMA 8405 GLT, TMG 45 B2RF) and two PROMALG genotypes from the Federal University of Uberlândia - UFU (UFU - H, UFU - P). DBC was used, arranged in a 10x3 factorial scheme, with the first factor being the genotypes and the second being the thirds. After the cotton cycle, the seeds of the genotypes were harvested in each third and the analysis of germination, of normal strong seedlings, and growth of the aerial and root part of plants was carried out. The data were submitted to analysis of variance and average comparison test. It was observed that both genotypes and thirds of cotton influence the physiology and morphology of seedlings. Therefore, the lower third has the best germination index (93 to 98% germination), when compared to the middle (88 to 97%) and upper third (88 to 97%). Indicating that to obtain uniform seed lots, it is necessary to take into account the third and the genetics of the plants. The thirds and the genotypes affect the physiological and morphological quality of the seeds, being the lower third with the best performance among the genotypes.