Phenotypic Diversity of Ethiopian Barleys in Relation to Geographical Regions, Altitudinal Range, and Agro-Ecological Zones: As an Aid to Germplasm Collection and Conservation Strategy

Kenya lies within sorghum centre of diversity. However, information on the relative extent of diversity patterns within and among genetically defined groups of distinct ecosystems is lacking. The objective was to assess the structure and phenotypic diversity of wild sorghum populations across a range of geographical and ecological conditions in the country. Sixty-two wild sorghum populations (30 individuals per population) sampled from four distinct sorghum growing regions of Kenya and covering different agroecologies were characterized for ten qualitative traits. Plant height, number of tillers, panicle sizes and flag leaf dimensions were also recorded. Frequencies of the phenotypic classes of each character were calculated. The Shannon diversity index (H′) was used to estimate the magnitude of diversity. Principal component analysis was used to differentiate populations within and between regions. Wild sorghum is widely distributed in Kenya, occurring in sympatric ranges with cultivated sorghum, and both have overlapping flowering windows. All characters considered displayed great phenotypic diversity. Pooled over characters within regions, the mean H′ ranged between 0.60 and 0.93 in Western and Coast regions, respectively. Wild sorghum was found to show a weak regional differentiation, probably reflecting the importance of seed-mediated gene flow in shaping the wild sorghum population structure. Trait distribution was variable among regions, but there was no conspicuous distribution of the traits studied in any given region. Spontaneous hybridization and introgression of genes from cultivated to wild sorghum seems to be likely, and may already have occurred for a long time, although undocumented. Implications for in situ and ex situ genetic resources conservation are discussed.

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Agro-ecological distribution of the phenotypic diversity of aerial yam (Dioscorea bulbifera L.) in Cameroon using multivariate analysis: prospect for germplasm conservation and improvement

Open Agriculture ◽

10.1515/opag-2018-0020 ◽

2018 ◽

Vol 3 (1) ◽

pp. 190-206 ◽

Cited By ~ 1

Author(s):

Eric B. Kouam ◽

Marie L. Avana-Tientcheu ◽

Vanessa D. Lekeumo ◽

Hermine M. Akitio ◽

Damase P. Khasa ◽

...

Keyword(s):

Multivariate Analysis ◽

Genetic Variability ◽

Phenotypic Diversity ◽

Germplasm Conservation ◽

Group Method ◽

Crop Species ◽

Humid Forest ◽

Ecological Zones ◽

Dioscorea Bulbifera ◽

Agro Ecological Zones

Abstract Aerial yam (Dioscorea bulbifera L.) is a crop of great economic importance and an excellent candidate for improving food security in developing countries. Understanding the genetic variability of any crop species is a decisive step for its improvement and requires characterization and evaluation of available germplasm. The objectives of this study were to determine the extent of genetic variability, estimate the association between agromorphological traits and clustering among 57 genotypes of aerial yam from three distinct agro-ecological zones in Cameroon using multivariate analysis. Thirty nine characters (23 qualitative and 16 quantitative) were used for the study. Significant differences in genetic diversity indices were found. Accessions from the bimodal humid forest zone (Na = 2.08, He = 0.27) showed significantly lower diversity compared to both western highland (Na = 2.30, He = 0.34) and humid monomodal forest zones (Na = 2.57, He = 0.32). Means values of most quantitative traits also showed significant differences between agro-ecological zones. Batingla-3 and Bawouwoua-1 had important bulbil yield, reaching 3500 g / plant. Significant associations were found between many traits. The use of the Unweighted Pair Group Method with Arithmetic Mean allowed the distribution of the 57 genotypes into six distinct clusters with the clustering pattern not showing any parallelism with location sites or agro-ecological zones. Mahalanobis D2 statistics revealed the highest inter-cluster distance between cluster II and VI. Accessions of these clusters are potential parents for future breeding programs. This study showed that aerial yam from Cameroon has an enormous wealth of traits variation, indicating huge potential for its genetic improvement through selection and hybridization.

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Phenotypic diversity and relationships among a worldwide durum wheat (Triticum turgidum L. var. durum) germplasm collection under rainfed conditions of Iran

Crop and Pasture Science ◽

10.1071/cp12403 ◽

2013 ◽

Vol 64 (2) ◽

pp. 87 ◽

Cited By ~ 1

Author(s):

Reza Mohammadi ◽

Ahmed Amri

Keyword(s):

Durum Wheat ◽

Phenotypic Diversity ◽

Crop Improvement ◽

Germplasm Collection ◽

Yield Potential ◽

High Yield ◽

Genetic Advance ◽

Geographical Regions ◽

Rainfed Conditions ◽

The Mean

Information on the variation available for different plant attributes has enabled germplasm collections to be effectively utilised in crop improvement. This study evaluated 380 durum wheat landraces, representing a worldwide durum wheat collection from 16 geographical origins, for several phenological and agronomic traits under rainfed conditions of Iran during three consecutive cropping seasons (2008–11). The experimental design was an unreplicated trial for all landraces, augmented by four repeated check cultivars. Best linear unbiased predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. Multivariate analyses were used to measure the phenotypic diversity within the germplasm collection and relationships among landraces from different geographical regions. Combined analysis of variance indicated significant differences between years, landraces, and their interaction effects, indicating high variability among the germplasm across the years for each studied trait. Low heritability coupled with low genetic advance as a percentage of the mean was observed for days to heading (DTH) and days to maturity (DTM), whereas moderate heritability with moderate genetic advance as a percentage of the mean was exhibited for grain yield (YLD) followed by 1000-kernel weight (TKW) and plant height (PHT). According to Shannon’s phenotypic diversity index, collections from Iran (which represented a high percentage of germplasm tested) exhibited lower diversity in quantitative traits, especially for phenological traits, i.e. DTH and DTM, relative to landraces from other origins. Biplot analyses indicated several significant patterns among landraces from different geographical regions. The landraces with American and Australian origins were closely associated with each other and can be characterised by low yield productivity, high PHT, and high infestation by wheat stem sawfly (WSS). In contrast, the germplasm from Asian origins showed high yield potential and high TKW with good tolerance to WSS. The results indicated that the Iranian landraces with the lowest yield tend to be late in flowering and maturity. In conclusion, landraces with a wide genetic diversity were identified and can be used to achieve breakthrough in the durum wheat genetic improvement.

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Sugarcane Landraces of Ethiopia: Germplasm Collection and Analysis of Regional Diversity and Distribution

Advances in Agriculture ◽

10.1155/2018/7920724 ◽

2018 ◽

Vol 2018 ◽

pp. 1-18

Author(s):

Esayas Tena Gashaw ◽

Firew Mekbib ◽

Amsalu Ayana

Keyword(s):

Smallholder Farmers ◽

Phenotypic Diversity ◽

Diversity Index ◽

Regional Distribution ◽

Germplasm Collection ◽

Juice Quality ◽

Regional Diversity ◽

Geographical Regions ◽

Wide Range ◽

Range Of Variation

Sugarcane has been cultivated by smallholder farmers since 16th century in Ethiopia and preceded the commercial production. However, as far as this study is concerned, no exploration and collection have been conducted to know the landraces and study the regional diversity of the crop. Therefore, the objectives of this study were to collect native sugarcane landraces in Ethiopia and to assess phenotypic diversity and analyze regional distribution among landraces collected from different geographical regions. More than 300 sugarcane genotypes were collected. The landraces were analyzed for 21 quantitative stalk and juice quality characters and 16 qualitative characters. Phenotypic diversity among landraces was high, as expressed by the large range of variation for mean quantitative traits and the high (0.80) Shannon–Weaver diversity index. Our results provided experimental evidence on occurrence of geographical variation and significant within-region variation where it was high in the regions of Amhara, Benshangul-Gumz, and SNNPR. Wide variability of agronomically important characters in sugarcane such as millable stalk count at harvest, single cane weight, and plant height was observed among regions. These characters also demonstrated high correlation with cane and sugar yield and the altitude of the collection sites. Therefore breeders can utilize accessions of regions showing variability for these characters in selection programs and to design breeding strategies to produce varieties with best commercial merits. The present study contributes to updating sugarcane descriptors adopted from USDA-ARS as well as Bioversity passport data for the future collection and evaluation. The paper discussed insinuation of the results with regard to plant breeding, germplasm collection, and conservation as well as the plausible sources for the wide range of variation observed. This is the first study to report landrace sugarcane genetic resources in Ethiopia and information on geographical pattern of variation in Ethiopian local sugarcane germplasm.

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Differential Adaptation Strategies By Agro-Ecological Zones In African Livestock Management

10.1596/1813-9450-4601 ◽

2008 ◽

Cited By ~ 3

Author(s):

S. Niggol Seo ◽

Robert Mendelsohn ◽

Ariel Dinar ◽

Pradeep Kurukulasuriya

Keyword(s):

Adaptation Strategies ◽

Ecological Zones ◽

Livestock Management ◽

Differential Adaptation ◽

Agro Ecological Zones

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Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

Sustainability ◽

10.3390/su13126910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6910

Author(s):

Adil Dilawar ◽

Baozhang Chen ◽

Arfan Arshad ◽

Lifeng Guo ◽

Muhammad Irfan Ehsan ◽

...

Keyword(s):

Pearson Correlation ◽

Principal Component ◽

Mitigation Strategies ◽

Precipitation Extremes ◽

Climate Mitigation ◽

Mean Annual Temperature ◽

Climate Extreme ◽

Ecological Zones ◽

The Mean ◽

Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

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Stock and stability of organic carbon in soils under major agro-ecological zones and cropping systems of sub-tropical India

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2021.107317 ◽

2021 ◽

Vol 312 ◽

pp. 107317

Author(s):

Nirmalendu Basak ◽

Biswapati Mandal ◽

Ashim Datta ◽

Manik Chandra Kundu ◽

Arvind Kumar Rai ◽

...

Keyword(s):

Organic Carbon ◽

Cropping Systems ◽

Ecological Zones ◽

Agro Ecological Zones

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Diverse symbiovars nodulating Cowpea (Vigna unguiculata) in highly adaptable agro-ecological zones in Mozambique

Systematic and Applied Microbiology ◽

10.1016/j.syapm.2021.126220 ◽

2021 ◽

pp. 126220

Author(s):

Margarida G. Simbine ◽

Sanjay K Jaiswal ◽

Felix D. Dakora

Keyword(s):

Vigna Unguiculata ◽

Ecological Zones ◽

Agro Ecological Zones

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Comparative Experimental Effects of Intercropping and Cypermethrin on Insect Pest Infestation and Yield of Maize, Cowpea and Okra in Two Cameroonian Agro-Ecological Zones

AgriEngineering ◽

10.3390/agriengineering3020025 ◽

2021 ◽

Vol 3 (2) ◽

pp. 383-393

Author(s):

Patient Farsia Djidjonri ◽

Nukenine Elias Nchiwan ◽

Hartmut Koehler

Keyword(s):

Field Experiments ◽

Insect Pests ◽

Cropping Systems ◽

Insect Pest ◽

Maize Yield ◽

Ecological Zones ◽

Pest Infestation ◽

Final Yield ◽

Cropping Seasons ◽

Agro Ecological Zones

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.

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