Ploidy Level and Genetic Parameters for Phenotypic Traits in Bermudagrass (Cynodon spp.) Germplasm

Abstract

Bermudagrass (Cynodon spp.) is a forage and turf crop commonly used worldwide. The USDA bermudagrass germplasm set is composed of plant introductions (PI’s) collected around the world and contains different Cynodon species, primarily C. dactylon. The collection was screened in a replicated trial in Florida for forage yield, leaf width, nutritive value (NV), and Bermudagrass Stem Maggot (Atherigona reversura) (BSM), which is an invasive pest to the southeastern United States that damages bermudagrass fields. The goal of this research was to determine ploidy level and genome size in this USDA collection, and evaluate the influence of ploidy level in the estimation of genetic parameters for BSM, leaf width, dry matter yield, and NV traits. For chromosome counts using classical cytogenetics techniques, root tips and meristems were collected from a set of PI’s with known ploidy. The PI’s and cultivars with known chromosome counts were used as internal standards to run flow cytometry and estimate genome size of the PI’s with unknown ploidy. Ploidy level was determined for all accessions and were used to estimate genetic parameters of phenotypic traits. By providing information on ploidy levels and genetic parameters, this research will support breeding efforts and future selections for forage bermudagrass.

A High-Quality Haplotype-Resolved Genome of Common Bermudagrass (Cynodon dactylon L.) Provides Insights Into Polyploid Genome Stability and Prostrate Growth

“…As a cross-pollinating plant, wild germplasms of C. dactylon collected at different regions usually show enormous genetical and morphological variations ( Wu et al, 2004 , 2007 ; Farsani et al, 2012 ; Tan et al, 2014 ; Zheng et al, 2017 ). Karyotype and molecular marker analyses not only revealed that polyploidy and aneuploidy events exist in C. dactylon but also pointed out the genome of C. dactylon is highly heterozygous ( Wu et al, 2006 ; Chaves et al, 2019 ; Grossman et al, 2021 ). These characteristics make C. dactylon an interesting plant material to investigate genome stability, variability, and evolution ( Khanal et al, 2017 ).…”

Moving warm‐season forage bermudagrass (Cynodon spp.) into temperate regions of North America

“…Large genetic variability is present in the core collection (Anderson et al, 2009). The core collection, in addition to several PIs obtained from GRIN, showed significant genetic variation for crude protein (CP), phosphorous concentration (P), in vitro digestible organic matter (IVDOM) and neutral detergent fibre (NDF) (Souza et al, 2020), and for yield and bermudagrass stem maggot (BSM, Atherigona reversura ) tolerance evaluated in Florida (Grossman et al, 2021). However, these two studies were limited to data collected in Florida, and there is a need to include data from other locations to make informed selections and release cultivars adapted to a broad range of environmental and management conditions in the transition zones.…”

“…tolerance evaluated in Florida (Grossman et al, 2021). However, these two studies were limited to data collected in Florida, and there is a need to include data from other locations to make informed selections and release cultivars adapted to a broad range of environmental and management conditions in the transition zones.…”

“…For instance, C. nlemfuensis can outcross with both C. dactylon and C. transvaalensis (de Wet & Harlan, 1970). All Cynodon species have a basic chromosome number of nine ( x = 9) and ploidy levels that range from 2n = 2x = 18 to 2n = 6x = 54 (Anderson et al, 2009; Grossman et al, 2021; Taliaferro et al, 1997). The current hybrid bermudagrass cultivars were developed decades ago by the pioneering work performed by Drs.…”

A Novel Beta-Glucosidase Gene for Plant Type Was Identified by Genome-Wide Association Study and Gene Co-Expression Analysis in Widespread Bermudagrass

“…As an important warm-season forage and turfgrass, bermudagrass is more variable in genome size and ploidy level, so the genetic and morphological diversity of abundant wild germplasm resources provides different varieties for bermudagrass breeding [ 10 , 11 ]. According to the development levels of shoots and stolons, wild bermudagrass are commonly divided into forage-types and turf-types based on different plant types [ 12 , 13 , 14 , 15 ].…”