Variability of early-season cold resiliency in Sorghum: Seed-to-Seed agro-morphological characterization

Authors: Emendack, Yves

Submitted to: Lecture
Publication Type: Other
Publication Acceptance Date: 2/10/2020
Publication Date: 2/10/2020
Citation: Emendack, Y. 2020. Variability of early-season cold resiliency in Sorghum: Seed-to-Seed agro-morphological characterization. Lecture. online.

Interpretive Summary: The physiological and agro-morphological responses of sorghum grown at three planting dates (early; April 1st, mid-early; May 1st, and normal; June 1st) in West Texas were characterized from seedling to maturity (seed-to-seed) using diverse lines and hybrids selected for cold tolerance at the early vegetative stage. These were evaluated in comparison with standard commercial cold tolerant hybrids and cold susceptible checks. Genotypic as well as source of tolerance variability for agro-physiological traits were observed within and across planting dates during seedling to the early developmental stages, and at maturity. All previously selected lines and hybrids for cold tolerance performed better than the cold susceptible checks. Some hybrids and lines outperformed standard commercial cold tolerant checks.

Technical Abstract: Low temperatures often affect plant growth and crop productivity which causes significant crop loses. Early planted sorghum usually experienced cooler night temperatures, which may result in delayed growth, floral initiation, and infertile pollen. These responses limit sorghum production in high altitudes, latitudes, and in regions with sub-optimal temperatures during early growth stages. Genetic variability for cold tolerance in sorghum has been measured by characterizing germination, emergence, vigor, and seedling growth under sub-optimal temperatures. However, the compounded effect of early season cold stress on plant growth and development as it relates to the genetic variability in potential grain yield loses (yield penalties) has not been evaluated. The physiological and agro-morphological responses of sorghum grown at three planting dates (early; April 1st, mid-early; May 1st, and normal; June 1st) in West Texas were characterized from seedling to maturity (seed-to-seed) using diverse lines and hybrids with different sources (Chinese landraces and Ethiopian converted germplasm) of cold tolerance selected at the early vegetative stage. These were evaluated in comparison with standard commercial cold tolerant hybrids and cold susceptible checks. Variability for agro-physiological traits and yield penalties were observed across planting dates for genotypes and the two agro-ecological sources of cold tolerance during seedling, early developmental stages, and at maturity. All previously selected cold tolerant lines and hybrids performed better than the cold susceptible checks. Some hybrids and lines outperformed the standard commercial cold tolerant checks. Thus, the development of molecular markers to screen for cold tolerance should not be limited to early seedling characterization but also consider agronomic traits that may affect yield penalties depending on the sources of tolerance.