Growing Degree Days during the Late Reproductive Phase Determine Spike Density and Cognate Yield Traits

Muhammad Umer Farooq,Iqra Ishaaq,Asim Ali Cheema,Muhammad Shahzad Afzal,Abdus Salam Khan,Asif Ali,Jianqing Zhu

doi:10.3390/agronomy8100217

Abstract

Drought has become more frequent in central Asia causing large losses in cereal yield. To surmount the existing problem, it is imperative to emphasize early maturing varietal development. However, the impact of heat units on spike morphology and its relationship with yield potential is still unclear. Thus, the current investigation was carried out to test wheat lines and varieties for variation in total heat unit’s accretion for anthesis and maturity and to understand the manipulating impact of sunlight on spike morphology, grain yield and its cognate traits. Furthermore, the gene action controlling major traits inheritance, combining ability effects, heritability, and association studies were also estimated. Following the Half Sib/Full Sib approach 27 hybrids along with 12 parents were tested. Results depicted broad variation in genetic stock. Correlation study demonstrated that earliness negatively affects the yield, while positively influencing spike density. Genetic variances were greater than variances due to environment, pointing to higher heritability (>50%) for all the characters except for grain’s weight spike−1. The degree of dominance revealed that the partial and over-dominant type of gene action conditioned inheritance of investigated traits. Thus, earliness can be used as an indirect selection criterion for yield advance.

Highlights

The primary concern of many researchers is about yield’s enhancement
It can be seen that the late reproductive phase manipulated the wheat yield as a strong and negative association seen
Combination AARI-11 × E-114 proved to be the best hybrid, consuming lesser amounts of heat units while reaching its maturity and at the same time had maximum positive specific combining ability (SCA) estimates for spike density, grain weight and ×1000-kernel weight favored by association studies

Summary

Introduction

The primary concern of many researchers is about yield’s enhancement. During the past few decades, the improvement in production is not as obvious as it was half a century ago, while the increase in population is at its highest [1]. No significant new growing areas will be incorporated in the future, nor will the contribution of management practices be noteworthy enough to improve yield, due to environmental and economic concerns. The apparent trend in current production showed a negligible increase in average yields. There is a need to employ alternative approaches for yield improvement. It could be possible either by nutrient supplementation in crop species (biofortification) [3] or by direct or indirect selection criterion for yield improvement.

Methods

Results

Conclusion