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A QUANTITATIVE GENETIC EVALUATION OF S(1) PROGENIES FROM A RANDOM-MATING SORGHUM POPULATION GROWTH UNDER IRON-DEFICIENT GROWTH CHAMBER AND FIELD CONDITIONS
Abstract
One-hundred S$\sb 1$ families from the sorghum (Sorghum bicolor (L.) Moench) population NP21R were evaluated for resistance to iron-deficiency chlorosis when grown under field and growth chamber conditions. The field experiment was grown at Garden City, Kansas, in 1983 and 1984 on a Manter sandy loam (coarse-loamy, mixed, mesic Aridic Argiustoll) soil. Seedlings also were screened in nutrient solutions under iron-deficient conditions in growth chamber experiments. Leaf chlorosis was rated using a scale of 1 (no chlorosis) to 5 (severe chlorosis) in both environments. Chlorosis ratings were taken every other day in the field (21 to 57 days after planting) and every day in the growth chamber (7 to 16 days after plants were placed in treatment containers). Heritabilities estimated on a S$\sb 1$ family (plot)-mean basis over 2 years were 0.66 $\pm$ 0.15, 0.86 $\pm$ 0.15, and 0.87 $\pm$ 0.15 for the first, maximum, and average chlorosis ratings, respectively. Theoretically, the mean maximum chlorosis rating for the population could be reduced to 1.0 after four cycles of selection and recombination. Agronomic traits were evaluated for S$\sb 1$ families in the field with and without foliar applications of iron. The iron amendment consistently decreased the number of days to flowering and the number of heads plant$\sp{-1}.$ The iron amendment consistently increased plant height, grain yield, seed weight, seed protein, seeds plant$\sp{-1}$, seeds head$\sp{-1}$, grain yield plant$\sp{-1}$, and grain yield head$\sp{-1}$, but treatment differences were significant for grain yield and grain yield plant$\sp{-1}$ only. Regression analysis indicated that the foliar-iron amendment significantly increased grain yield, grain yield plant$\sp{-1}$, grain yield head$\sp{-1}$, seeds plant$\sp{-1}$, seeds head$\sp{-1}$, and plant height by 32.4, 29.4, 28.4, 27.4, 26.6, and 5.5%, respectively, and decreased days to flowering by 3.2% for each unit increase in the average S$\sb 1$ family chlorosis rating value. Of the growth chamber chlorosis ratings, heritability was highest for the average chlorosis rating (0.65 $\pm$ 0.16) on a plants-within-plots basis (four plants per S$\sb 1$ plot). The correlations between field and growth chamber chlorosis ratings were nonsignificant compared over the population. However, some blocks of S$\sb 1$ families within the experiment had significant correlations between field and growth chamber chlorosis ratings.
Subject Area
Agronomy
Recommended Citation
WILLIAMS, ERIC P, "A QUANTITATIVE GENETIC EVALUATION OF S(1) PROGENIES FROM A RANDOM-MATING SORGHUM POPULATION GROWTH UNDER IRON-DEFICIENT GROWTH CHAMBER AND FIELD CONDITIONS" (1987). ETD collection for University of Nebraska-Lincoln. AAI8719788.
https://digitalcommons.unl.edu/dissertations/AAI8719788