Caracterização fenotípica da germinação na précolheita em trigo em uma população de linhagens endogâmicas recombinantes.

Abstract

Pre-harvest sprouting in wheat represents a problem that affects high humidity wheat regions, with high temperatures and frequent rain at grain maturity stage. Wheat breeding is very important, aiming to create new cultivars resistant to this phenomenon, because the problem causes economic prejudices in the cereal production, diminishing grain yield and quality. In this sense, this study has as objective to characterize phenotypically a population of wheat recombinant inbred lines in F6 generation, analyzing the characters of agronomic importance and their relationship with pre-harvest sprouting. The experiment was conducted in 2017, at experimental field of the Centro de Genômica e Fitomelhoramento located at the Centro Agropecuário da Palma, from the Universidade Federal de Pelotas (UFPel), municipality of Capão do Leão – Rio Grande do Sul, Brazil. A population constituted by 398 genotypes, as well as it genitors, Quartzo x Marfim, contrasting for pre-harvest sprouting character, was evaluated for the following characters: days to heading (DAE), plant height (EST), days to maturity (DAM), percentage of lodging (ACM), spike length (SL), spike weight (SW), spikelet number (SN), number of spikelets per spike (NEE), weight of grains per spike (PGE), thousand kernel weight (PMG), visual germination (GEV) and percentage of germinated grains (GEQ). Descriptive statistics analyzes, frequency distribution and correlation analysis were made. Concerning to pre-harvest sprouting character, an analysis of frequencies divided the population in 14 classes, which evidences the high variability represented by 59% of genotypes as transgressive segregants surpassing their parents. Note that there is a high correlation between the characters related to spike weight (PE, PGE and NGE), and on the other hand, the percentage of germinated grains shows positive correlation with visual evaluation of germination (0.521); both methods allow classifying the genotypes regarding pre-harvest sprouting tolerance. The formed population shows promise for both the development of superior genotypes as well as the QTL mapping population for pre-harvest sprouting tolerance.