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Pollen production in relation to genotypic and environmental influences in maize
Abstract
Selection of good male parents with adequate pollen production is important in plant breeding and seed production programs. The objectives of this research were to develop methods to quantify pollen production; identify genetic and environmental factors influencing maize pollen production, and traits determining pollen yield; estimate pollen fertility and pollen production relationships; and conduct genetic studies on pollen and grain yield components. Bagging method was effective in measuring total amount of pollen. Exotic progeny produced 6.12 g plant$\sp{-1}$ whereas Corn Belt progeny produced 3.2 g plant$\sp{-1}.$ Exotic genotypes exhibited a longer duration of shedding of pollen (13 days) as measured by both bagging and direct methods. Traits were more responsive to genetic variability than to environmental effects. Time of planting was not a good estimator of environmental variation. A rate of pollen shedding to silking of 0.3 g plant$\sp{-1}$ day$\sp{-1},$ and 0.2 g plant$\sp{-1}$ day$\sp{-1}$ during the entire period was identified in parents by the phenological model. Sufficient pollen to ensure pollination was present when 971 and 1118 growing degree units in exotic and Corn Belt parents were accumulated from planting to silking. Total male flowers per plant, flowers per branch, flowers in main spike, and branch number were identified as the most important traits determining pollen yield. Phenotypic plasticity on tassel traits was expressed. Pollen fertility was neither dependent on shed span nor affected by pollen size. Moderate associations between pollen and fertility traits, and seed-set traits were found (r = 0.28 to 0.74). The heterosis study indicated Corn Belt genotypes possessed better combining ability for pollen yield components, while exotic genotypes exhibited good combining ability for grain yield components, and both expressed additive and non-additive genetic effects. However, dominant effects prevailed. Knowledge of pollen process, pollen production traits, pollen-fertility relationships, and genetic studies can be useful in hybrid seed production program and during early stages of selection, when good performance of male parents lines is required for maize breeders.
Subject Area
Agronomy|Genetics|Botany
Recommended Citation
Vidal-Martinez, Victor Antonio, "Pollen production in relation to genotypic and environmental influences in maize" (1997). ETD collection for University of Nebraska-Lincoln. AAI9736957.
https://digitalcommons.unl.edu/dissertations/AAI9736957