Biology subjects

Habte, E.

Publications and source records attributed to Habte, E..

3 recordsLinked to original sources

bioRxiv2024

Whole genome resequencing of a global collection of Napier grass (Cenchrus purpureus) to explore global population structure and QTL governing yield and feed quality traits

Napier grass (Cenchrus purpureus) is a C4 perennial grass species native to Sub-Saharan Africa (SSA), primarily used to feed cattle in SSA. In this study, we sequenced the genomes of 450 Napier grass individuals, sourced from 20 different countries. More than 170 million DNA variants (SNPs and Indels) were detected, of which [~]1% informative SNPs were used to assess genetic diversity in the collection. Our resequencing study provided valuable insights into the genetic diversity across a global Napier grass collection. Furthermore, a genome-wide association study on two independent populations, identified multiple quantitative trait loci (QTL) that were significantly associated with desirable agronomic traits, such as biomass yield, nitrogen and cellulose content. Therefore, our results will serve as a valuable resource in safeguarding and unravelling the patterns of Napier grass genetic diversity, in the face of climate change, and spearhead genomics-based breeding programs to develop high-yielding and drought-tolerant varieties suitable for forage and biofuel production.

plant biology↗

bioRxiv2023

A population genomics approach to unlock the genetic potential of lablab (Lablab purpureus), an underutilized tropical forage crop

BackgroundIn Sub-Saharan Africa (SSA) livestock production and productivity are severely restricted by the scarce supply of feedstuffs and forage crops, while those available are often of low nutritional quality resulting in poor animal productivity and leading to widespread malnutrition among the public, particularly women and children. Traditionally, several tropical forage crops have been used in the region both in the rangelands and as cut-and-carry cropping systems, but limited research attention has been paid to improve the quality of and access to these animal feeds. Lablab (Lablab purpureus (L.) is one of the conventionally grown multi-purpose underutilized crops that originated in Africa. It is an annual or short-lived perennial multi-purpose forage legume which has versatile uses (as a vegetable and dry seed), and as feed for animals, or as green manure. To develop new and highly productive lablab varieties, using genomics-assisted selection, the present study aimed to identify quantitative trait loci (QTL) associated with agronomically important traits in lablab and to assess the stability of these traits across two different agro-ecologies in Ethiopia. ResultsOne hundred and forty-two cultivated and wild lablab accessions displayed significant agro-morphological variation in eight analysed traits, including plant height, total fresh weight, and total dry weight. Further, the agronomic performance of the accessions was significantly different across locations and years, highlighting the substantial genotype-by-environment interactions. The population genetic structure of the lablab accessions, based on half a million high quality single nucleotide polymorphisms (SNPs), revealed an independent domestication pattern for two-seeded and four-seeded lablab accessions. Furthermore, based on multi-environmental trial data, a genome-wide association study (GWAS) identified useful SNPs and k-mers for yield-related traits, such as plant height and total dry weight. ConclusionsGenomic-assisted breeding is playing a key role in accelerating trait improvement in temperate forages, such as perennial ryegrass and alfalfa. Here we show that a similar approach could benefit underutilized crops such as lablab. The publicly available genomic tools and field evaluation data from this study will offer a valuable resource for plant breeders and researchers, to initiate genomic-assisted breeding in lablab which will fast-track genetic gain per unit time and ultimately contribute towards achieving food/nutritional security in the region.

genomics↗

bioRxiv2021

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

Napier grass is the most important perennial tropical grass native to Sub-Saharan Africa and widely grown in tropical and subtropical regions around the world, primarily as a forage crop for animal feed, but with potential as an energy crop and in a wide range of other areas. Genomic resources have recently been developed for Napier grass that need to be deployed for genetic improvement and molecular dissection of important agro-morphological and feed quality traits. From a diverse set of Napier grass genotypes assembled from two independent collections, a subset of 84 genotypes that best represents the genetic diversity of the collections were selected and evaluated for two years in dry (DS) and wet (WS) seasons under three soil moisture conditions: moderate water stress in DS (DS-MWS); severe water stress in DS (DS-SWS) and, under rainfed (RF) conditions in WS (WS-RF). Data for agro-morphological and feed quality traits, adjusted for the spatial heterogeneity in the experimental blocks, were collected over a two-year period from 2018 to 2020. A total of 135,706 molecular markers were filtered, after removing markers with missing values > 10% and a minor allele frequency (MAF) < 5 %, from the high-density genome-wide markers generated previously using the genotyping by sequencing (GBS) method of the DArTseq platform. A genome-wide association study (GWAS), using two different mixed linear model algorithms, identified more than 58 QTL regions and markers associated with agronomic, morphological and water-use efficiency traits. QTL regions governing purple pigmentation and feed quality traits were also identified. The identified markers will be useful in the genetic improvement of Napier grass through the application of marker-assisted selection and for further characterization and map-based cloning of the QTLs.

genetics↗