Department of Crop Science

Characterisation and Widening of the Genetic Base of Tiger Nut (Cyperus Esculentus L.) by Chemical Mutagenesis

Sat, 01 Jun 2024 00:00:00 GMT

Characterisation and Widening of the Genetic Base of Tiger Nut (Cyperus Esculentus L.) by Chemical Mutagenesis Twumasi, Patrick Limited information exists regarding the diversity of tiger nuts (Cyperus esculentus L.) in Ghana, hindering potential improvements. To address this gap, an assessment of genetic diversity was conducted using 11 morpho-descriptors and nine simple sequence repeat (SSR) markers to explore variability among and within the accessions to provide valuable insights for further breeding through mutagenesis. A total of 42 accessions were collected from major tiger nut growing areas in Ghana and these were planted in the field using a randomized complete block design (RCBD) with 3 replications. The results from the field characterization showed significant differences among the accessions for some traits studied. The use of SSR markers demonstrated high mean polymorphism of 0.78. UPGMA cluster analyses of both morphological and molecular data indicated low genetic variability within the accessions. Four high-yielding accessions were identified for potential improvement through mutagenesis. Subsequently, 400 tubers of the four genotypes (two brown and two black tuber-producing) underwent treatment with ethyl methanesulfonate (EMS) and colchicine at various concentrations. Analysis of quantitative data revealed LD50 and RD50 values for mass treatmeant of tiger nut tubers with the mutagens. Subsequently, 600 tubers of the four selected genotypes were mass-treated with EMS and colchicine mutagens following the LD50 and RD50 values determined, and were field-planted for M1V1 to M1V4 generations. Twenty-one mutants have beeen identified for breeding enhancement and possible varietal release. xxii, 188p:, ill.

Widening the Genetic Base of Cowpea Germplasm Through Gamma Rays Mutagenesis

Thu, 01 Dec 2022 00:00:00 GMT

Widening the Genetic Base of Cowpea Germplasm Through Gamma Rays Mutagenesis Lumorh, Prosper Deo-Donne The genetic diversity of cowpea is narrow because the crop is self-pollinated. Gamma rays were used to increase genetic diversity of Hansadua, WC-36, ACC122WxWC-10, IT97K-819 and WC-10 parental genotypes. Selecting for earliness, high yields, disease resistance and high nutritional contents compared to parental controls and checks were done at M4 generation. The results showed significant wide variations in the responses of cowpea genotypes to gamma ray doses as LD50 and RD50. The estimated LD50 values were Hansadua (452.0 Gy), WC-36 (662.0 Gy), ACC122WxWC-10 (694.0 Gy), IT97K-819 (590.5 Gy) and WC-10 (591 Gy). Hansadua was the most sensitive to gamma radiation. The mass irradiation at the respective LD50 and RD50 values induced plant architecture to vary from indeterminate to determinate, semi-erect to acute erect, prostrate, spreading and some twinning. An increase in yields from 3.7t/ha in parent to 5.8t/ha in HanM4(12)(25) was observed. The ash values ranged from 2.93-3.56%, with HanM4(17)(1W) being highest. Carbohydrates ranged from 58.27-69.73% with HanM4(12)(5) being highest and protein ranged from 19.09-30.53% from the parental control with the highest in HanM4(12)(3). All the putative mutants were early maturing with days to 50% maturity of 42 to 61 days. HanM4(17)(1W) had 21.7% incidence of brown rust while HanM4(41)(HY31) recorded 10% incidence of golden mosaic disease. The results confirmed gamma ray induction can enhance yields, nutritional components, early maturity and disease tolerance/resistance of cowpea. xx 183p:, ill

Marker-Assisted Breeding For Resistance To Blast And Rice Yellow Mottle Diseases In Ghana

Mon, 01 Jul 2024 00:00:00 GMT

Marker-Assisted Breeding For Resistance To Blast And Rice Yellow Mottle Diseases In Ghana Ofosu, Kirpal Agyemang Rice is consumed by over half of the world’s population and accounts for 19% of calorie intake. Biotic stresses cause substantial yield losses in rice. Rice blast and Rice yellow mottle disease (RYMD) are the two main biotic stressors in sub-Saharan Africa. In Ghana, the major rice varieties cultivated by farmers namely, CRI-Agra Rice, CRI-Amankwatia, Jasmine 85 and Togo Marshall are susceptible to blast and Rice yellow mottle virus (RYMV) diseases and can cause up to 100% yield losses. There is thus the need to tackle these two diseases in order to reduce these yield losses. The objective of this research was to introgress resistance genes for rice blast and RYMD into four popular aromatic rice varieties in Ghana. To achieve this objective, a donor parent, Gigante which had RYMV1 (rymv1-2) and blast (Pi54) resistance genes was crossed to the four popular aromatic rice varieties to produce BC3F2 populations. A total of 71 BC3F2 rymv1-2 and Pi54 introgressed lines were screened for resistance to RYMV and blast and evaluated in a Preliminary Yield Trial (PYT). All the lines were found to be highly resistant to RYMV and rice blast. The results of the PYT indicated that RYMV-B-03-84-36-10-57, RYMV-B-01-6-37-1-91 and RYMV-B-03-84-36-10-46 yielded 7.25 ton/ha, 7.23 ton/ha, and 7.12 ton/ha respectively, which were significantly higher (P<0.05) than the highest yielding recurrent parent, CRI-Agra Rice (7.09 ton/ha). Through marker-assisted backcrossing, lines that are resistant to rice blast and Rice yellow mottle disease were produced. These can be evaluated further and released as resistant versions of the four popular but susceptible aromatic varieties. xviii, 184p; , ill.

Study Of Okra Leaf Curl Disease And Its Whitefly Vector (Bemisia Tabaci) Vector In Three Agro-Ecological Zones In The Volta And Oti Regions Of Ghana

Sat, 01 Jul 2023 00:00:00 GMT

Study Of Okra Leaf Curl Disease And Its Whitefly Vector (Bemisia Tabaci) Vector In Three Agro-Ecological Zones In The Volta And Oti Regions Of Ghana ADZIM, CHARLES AMANKWA Coat protein Incidence Insecticide Okra leaf curl disease Okra yellow crinkle virus Pesticide Polymerase Chain Reaction (PCR) Sequencing Severity Whitefly xxiii,288p:, ill.