Imtiaz Ahmad

Document Type

Thesis - University Access Only

Award Date

1994

Degree Name

Master of Science (MS)

Department / School

Agronomy

Abstract

It has been demonstrated that there is a direct effect on the size and weight of kernels by certain pollen parents (20). If these effects influence yield they are of practical interest to hybrid seed maize producers and farmers. Also, direct effects of pollen parent could be important in studies on the inheritance of kernel size. -Xenia is the change in characters of endosperm due to the immediate effect of foreign pollen. It may be thought of in terms of qualitative changes in endosperm. Traits of the developing embryo may also be affected by alleles from foreign pollen. Since the embryo and endosperm are nonmaternal tissue, the ability of the endosperm and embryo to assimilate solutes is affected by their genotypes. Therefore, the genotype of the embryo and endosperm tissue influence the effectiveness of the kernel as a sink. If utilization of the nutrients provided by the maternal parent is affected by embryo and endosperm genotype of the developing kernels, then outcrossed kernels may be more effective as a sink than kernels arising from self pollination. Thus, kernel weight and grain yield may be affected by the paternal parent (15,17,22,27). Increased kernel weight with pollination from an outside pollen source compared to self-pollinated kernels have been found in some tests (1,3,5). Pollination from such sources could increase chances of heterozygosity in the embryo and endosperm genotypes (12,15). Kiesselbach and Leonard (15) indicated that differences in kernel weight might not relate to yields per plant or acre because differences in kernel weight within an ear might merely reflect competition between kernels varying in vigor of growth (15). It has been suggested that variety tests as commonly conducted, permitting promiscuous pollination between neighboring varieties, are affected by foreign pollen (1,3,20). It has also been suggested that farmers may increase their grain yield by planting a mixture of varieties so that cross pollination will occur (27). The condition and extent that kernel weight and ear weight are affected by the genetic similarity between pollen and ovule is not well documented. The objectives of this study were to determine the effects of pollen source on the grain production of maize on a per kernel basis, a per ear basis and a grain yield per unit area basis.

Library of Congress Subject Headings

Corn -- Yields

Corn -- Pollen

Corn -- Breeding

Format

application/pdf

Number of Pages

73

Publisher

South Dakota State University

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