Forage Performance and Detection of Marker Trait Associations with Potential for Napier Grass (Cenchrus purpureus) Improvement

Abstract

The evaluation of forage crops for adaptability and performance across production systems and environments is one of the main strategies used to improve forage production. To enhance the genetic resource base and identify traits responsible for increased feed potential of Napier grass, forty-five genotypes from Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Brazil, were evaluated for forage biomass yield and feed nutritional quality in a replicated trial under wet and dry season conditions in Ethiopia. The results revealed significant variation in forage yield and feed nutritional qualities among the genotypes and between the wet and dry seasons. Feed fiber components were lower in the dry season, while crude protein, in vitro organic matter digestibility, and metabolizable energy were higher. Based on the cumulative biomass and metabolizable energy yield, top performing genotypes were identified that are candidates for future forage improvement studies. Furthermore, the marker-trait association study identified diagnostic single nucleotide polymorphisms (SNP) and SilicoDArT markers and potential candidate genes that could differentiate high biomass yielding and high metabolizable energy genotypes in the collection.

Insights into the genetic architecture of complex traits in Napier grass (Cenchrus purpureus) and QTL regions governing forage biomass yield, water use efficiency and feed quality traits

“…Similarly, thirteen markers were detected for ADF, NDF and ADL, which are mainly linked with the cell wall components of fibre and lignin that negatively affect the feed nutritional quality. Improving the digestibility of forages by reducing lignin and fibre is a major goal in forage crop breeding programs (Habte et al, 2020; Rocha et al, 2019).…”

“…Overall, 12 harvests were conducted, following every eight weeks of regrowth, in both WS and DS conditions. Data of morphological, agronomic, and feed quality traits were collected from three randomly selected plants per row in each of the three soil moisture conditions, as described in (Habte et al, 2020). The agro-morphological traits collected were plant height (PH) in centimeter (cm), leaf length (LL) in cm, leaf width (LW) in millimeter (mm), stem thickness (ST) in mm, tiller number (TN) count, internode length (IL) in cm, total fresh weight (TFW) in t/ha, total dry weight (TDW) t/ha, leaf-stem-ratio (LSR), and water use efficiency (WUE) in g/l (Dry matter produced per liter of water).…”

“…Unlike classical linkage mapping that uses a population of the progeny of a biparental cross, GWAS is performed on a diverse collection of unrelated genotypes (Huang and Han, 2014; Flint-Garcia et al, 2003) and hence this technique is ideally suited to the study of genebank collections (McCouch et al, 2012). To date, only two GWAS studies on Napier grass have been reported (Habte et al, 2020; Rocha et al, 2019), in which markers associated with high biomass yield, metabolizable energy and biomass digestibility were detected. However, these studies had a limitation on either marker density or population size.…”

Breeding and Genetics of Forages for Semi-Arid and Arid Rangelands

“…immigrant established best in March and the Pustinny-Select population established best in May [17]. In contrast, the evaluation of Brazilian Napier grass genotypes in Ethiopia, resulted in substantial differences in forage yield and quality between wet and dry seasons, but also indicated that the genotypes with the greatest forage production were consistent across both seasons [18]. Thus, the effect of genotype × environment interaction on rangeland agriculture is species, genotype, location, and trait dependent.…”

“…Transcriptomic and proteomic techniques resulted in the identification of a number of candidates for the molecular improvement of alfalfa salinity tolerance [21]. Finally, marker-trait associations in Napier grass identified polymorphisms with potential utility for identifying genotypes with high agronomic performance [18]. Although the potential for marker-assisted and genomic selection is still untapped, these techniques show great promise as the efforts increase and receive more emphasis.…”