Ovary abortion is prevalent in diverse maize inbred lines and is under genetic control

Jeffery L Gustin,Susan K Boehlein,Janine R Shaw,A Mark Settles,L Curtis Hannah,Ashley Webster,Weschester Junior,William F Tracy

doi:10.1038/s41598-018-31216-9

Jeffery L Gustin, Susan K Boehlein + Show 6 more

Open Access

https://doi.org/10.1038/s41598-018-31216-9

Copy DOI

Abstract

Crop improvement programs focus on characteristics that are important for plant productivity. Typically genes underlying these traits are identified and stacked to create improved cultivars. Hence, identification of valuable traits for plant productivity is critical for plant improvement. Here we describe an important characteristic for maize productivity. Despite the fact mature maize ears are typically covered with kernels, we find that only a fraction of ovaries give rise to mature kernels. Non-developed ovaries degenerate while neighboring fertilized ovaries produce kernels that fill the ear. Abortion occurs throughout the ear, not just at the tip. We show that the fraction of aborted ovaries/kernels is genetically controlled and varies widely among maize lines, and low abortion genotypes are rare. Reducing or eliminating ovary abortion could substantially increase yield, making this characteristic a new target for selection in maize improvement programs.

Highlights

A grand challenge to our society is feeding the growing human population while facing unfavorable climate change
We show that genetic variation exists for ovary abortion, making this trait potentially amendable to genetic selection for improved yield in maize breeding programs
Prompted from observations of poor kernel set in experimental maize lines[9], we counted the number of kernels that failed to develop on ears of the 26 parental inbred lines of the maize Nested Association Mapping (NAM) population[10]

Summary

Introduction

A grand challenge to our society is feeding the growing human population while facing unfavorable climate change. Grain yield in maize is a product of individual kernel weight and kernel number; factors affecting them have received substantial attention[2,3,4,5,6]. Failure of kernels to develop from ovaries, here termed ovary abortion reduces grain number on the ear. The typical maize ear is covered with kernels, and their removal reveals no evidence of undeveloped ovaries or kernels. It is surprising, as documented here, that only 60 to 65% of the maize ovaries commonly give rise to a functional, developed kernel under typical field conditions. We show that genetic variation exists for ovary abortion, making this trait potentially amendable to genetic selection for improved yield in maize breeding programs

Methods

Results

Conclusion