Diversity of Ethiopian tetraploid wheat germplasm: breeding opportunities for improving grain yield potential and quality traits

2009 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yifru Teklu ◽  
Karl Hammer
Keyword(s):  
Total Variation ◽  
Phenotypic Diversity ◽  
Diversity Index ◽  
Tetraploid Wheat ◽  
Principal Component ◽  
Diversity Indices ◽  
Yield Potential ◽  
Wheat Improvement ◽  
Geographical Regions ◽  
Diversity Studies

In this paper, Shannon–Weaver diversity indices were employed to examine the phenotypic diversity in 271 Ethiopian tetraploid wheat accessions in relation to characters, regions of origin and altitude. Moreover, review of genetic diversity studies in Ethiopian tetraploid wheat was made to explore breeding opportunities. The diversity index varied widely across regions. Among the four altitudinal classes, the highest (0.72) and lowest (0.61) mean diversity indices were observed in altitude classes II and IV, respectively. The diversity index (H′) showed that most traits are polymorphic. The partitioning of the total phenotypic diversity into within- and among-region diversity indicated that 71% of the total variation was attributed to the within-region diversity. Principal component analysis was computed to examine the regional and altitudinal patterns of variation. On regional bases, the first four axes, whose eigenvalues are greater than 1, explained about 82% of the observed phenotypic diversity in the 271 tetraploid wheat accessions. On altitudinal bases, however, only the first two principal components explained 89.7% of the total variation. In general, phenotypic diversity showed considerable differences for each trait in different geographical regions and altitudinal classes which could be utilized in wheat improvement programmes. Breeding opportunities and strategies are suggested.

Transition management for organic agriculture under citrus cultivation favors fungal diversity in soil

2018 ◽  
Vol 35 (2) ◽  
pp. 120-127
Author(s):  
Juliana Cristina Scotton ◽  
Sérgio Kenji Homma ◽  
Wesley Luiz Fialho Costa ◽  
Diego Fontebasso Pelizari Pinto ◽  
José Silvio Govone ◽  
...  
Keyword(s):  
Organic Agriculture ◽  
Management System ◽  
Fungal Diversity ◽  
Diversity Index ◽  
Principal Component ◽  
Diversity Indices ◽  
Transition Management ◽  
Farming Practices ◽  
Soil Fungal Community ◽  
Innovative Solution

AbstractThe present international scenario recognizes organic agriculture as an innovative solution to reduce agrochemicals and practices that degrade the agroecosystem. Yet, the shift from an already well-established agricultural model to a relatively new one is a challenging task and requires further scientific support. This work investigated the influence of transitional management – TM (from conventional to organic agriculture) on the soil fungal community under citrus, in dry and rainy periods. From 2012 to 2015 on, an area in Mogi Guaçú, SP, Brazil was selected, and two treatments were installed: a conventional management (CM) system based on farming practices with agrochemicals and fertilizers use, and another, transition management (TM) based on a 25% reduction per year of the chemical substances used in CM, with soil conditioner bokashi introduced. The performance of the transition system was evaluated in the context of soil fertility and diversity index of fungal taxa, by plate culture isolation, through the richness of Margalef (Dmg), diversity of Shannon (H′) and reverse Simpson (D). Differences in the occurrence and frequency of Paecilomyces, greater under CM and Penicillium, greater under TM, highlighted the influence of the management system employed. Richness and diversity indices were higher under TM. Principal component analysis revealed that 49.9% of the differences in fungal diversity was due to the management system. Only 16.5% was a result of the season of sampling. Four years of reduction/replacement of chemical practices in TM was sufficient to modify and favor some soil fungal taxa and consequently their activity. This research brings promising results to organic agriculture initiatives with relevant results for a tropical climate area.

scholarly journals Geographical patterns of phenotypic diversity and structure of Kenyan wild sorghum populations (Sorghum spp.) as an aid to germplasm collection and conservation strategy

2010 ◽  
Vol 8 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Moses M. Muraya ◽  
Hartwig H. Geiger ◽  
Evans Mutegi ◽  
Ben M. Kanyenji ◽  
Fabrice Sagnard ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Diversity Index ◽  
Flag Leaf ◽  
Germplasm Collection ◽  
Principal Component ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Regional Differentiation ◽  
Wild Sorghum ◽  
Geographical Patterns

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.

scholarly journals Exploring morpho-physiological profiles of a collection of tomato (Solanum lycopersicum) germplasm using multivariate statistics

2020 ◽  
Vol 18 (2) ◽  
pp. 88-97
Author(s):  
Ifigeneia Mellidou ◽  
Konstantinos Krommydas ◽  
Irini Nianiou-Obeidat ◽  
Georgia Ouzounidou ◽  
Apostolos Kalivas ◽  
...  
Keyword(s):  
Solanum Lycopersicum ◽  
Phenotypic Diversity ◽  
Diversity Index ◽  
Total Yield ◽  
Morphological Characteristics ◽  
Principal Component ◽  
Fruit Shape ◽  
Qualitative Traits ◽  
Germplasm Collections ◽  
Wide Range

AbstractA selection of tomato (Solanum lycopersicum L.) genotypes with diverse origin and breeding history including 33 landraces, eight modern varieties and two commercial hybrids has been characterized using a set of 25 qualitative descriptors and six quantitative traits. A wide range of variation was evident for the majority of traits, highlighting their utility for characterizing tomato germplasm collections. A plethora of qualitative traits including type of leaf blade, depression and ribbing at peduncle end, fruit shape at blossom end, number of locules and flowering time, as well as measured traits with economic importance such as fruit fresh weight, firmness and total yield per plant, were found to be highly variable within the collection, with a diversity index greater than 0.8. Strong correlations were detected among several traits related to fruit yield and quality. Two-dimensional principal component analysis as well as the unsupervised hierarchical clustering grouped genotypes according to their phenotypic resemblance and morphological characteristics to a great extent. Landraces from different origins were scattered across the whole variation spectrum of PC1 and PC2. A set of six qualitative traits could efficiently discriminate cultivars in PCA (explaining 75% of total variation), suggesting that it can serve as a valuable breeding tool for the germplasm characterization. The evaluation of the phenotypic diversity in the collection as well as the identification of traits that contribute most to heterogeneity have important implications for establishing core collections with high diversity, as well as designing breeding schemes across the Mediterranean basin.

Phenotypic diversity of soybean (Glycine max (L.) Merr.)accessions in the Philippines for utilization

2016 ◽  
Author(s):  
Hidelisa De Chavez ◽  
Teresita Borromeo ◽  
Nic Oswald Borines ◽  
Renerio Jr Gentallan
Keyword(s):  
Coat Color ◽  
Phenotypic Diversity ◽  
Germplasm Collection ◽  
Principal Component ◽  
Diversity Indices ◽  
Morphological Characters ◽  
The Philippines ◽  
Soybean Germplasm ◽  
Plant Growth Habit ◽  
Qualitative Characters

An increasing trend of soybean production and consumption has been seen in the Philippines. To assess the potential of the soybean germplasm for utilization, diversity of the Philippine soybean collection was established. High diversity was marked on 17 out of 29 qualitative characters, which include plant growth habit, leaf blistering and flower standard color. Phenotypic diversity indices (H’) of 92 soybean accessions averaged at 0.62. This aside, traits identical to a variety of soybean with superior characters were all present in the soybean germplasm collection. Using simple matching similarity coefficient, cluster analysis separated the different accessions into 12 distinct clusters at 62% similarity. Categorical Principal Component Analysis (CATPCA) showed that two independent components accounted for 35.36% of the total variation of the qualitative morphological characters. Factor loadings for each component showed the morphological characters, such as pubescence color, flower wing color, and seed coat color, that were contributing to the high projections in the two principal components. Accessions with vigorous seedlings were also observed. With the marked trait diversity, the soybean collection could be potentially used directly and for breeding purposes. Consequently, to uncover further the potential of our genetic resources at hand, the remaining germplasm accessions at NPGRL should be characterized and evaluated

scholarly journals Diversity, Distribution and Density of Estuarine Phytoplankton in The Sundarban Mangrove Forests, Bangladesh

2012 ◽  
Vol 41 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Abdul Aziz ◽  
Mashrura Rahman ◽  
Ashfaque Ahmed
Keyword(s):  
Diversity Index ◽  
High Capacity ◽  
Principal Component ◽  
Diversity Indices ◽  
Mangrove Forests ◽  
Low Salinity ◽  
Wiener Diversity Index ◽  
Phytoplankton Communities ◽  
Sundarban Mangrove ◽  
Estuarine Phytoplankton

Diversity, distribution and density of estuarine phytoplankton from nine sites under four Ranges of the Sundarban Mangrove Forests (SMF), Bangladesh have been studied. The phytoplankton communities represented by 36 species which belonged to Chlorophyceae (3), Euglenophyceae (2), Bacillariophyceae (30) and Xanthophyceae (1). Occurrence of taxa and their densities were highest near the confluence of Hangsha River (R) with the river Murdat at Patcosta. Shannon-Wiener diversity index was also highest (H = 3.494) in this area. Lowest density of phytoplankton and diversity indices (H = 1.661) were found in Bal R., Bisandri Khal and Kalabogi R. Oocystis pusilla, Coscinodiscus excentricus, C. lineatus and Navicula brekkeansis occurred abundantly, while Cyclotella comta, Thalassionema nitzschioides and Lioloma delicatula were common. Coscinodiscus lineatus was distributed in all the nine sites including high and low tides indicating its high capacity to tolerate habitat fluctuations. Chaetoceros socialis was found only in Passur R. with low salinity, conductivity and total dissolved solids. The total numbers of phytoplankton individuals per liter were generally higher during low tide than those of high one. Principal Component Analysis (PCA) showed the relationship between pH and some species of phytoplankton DOI: http://dx.doi.org/10.3329/bjb.v41i1.11086 Bangladesh J. Bot. 41(1): 87-95, 2012 (June)

scholarly journals Evaluation of drought tolerance indices for barley landraces under irrigated and dry conditions

2020 ◽  
Vol 36 (5) ◽  
Author(s):  
Mehdi Feizi ◽  
Mahmood Solouki ◽  
Behzad Sadeghzadeh ◽  
Baratali Fakheri ◽  
Seyed Abolghasem Mohammadi
Keyword(s):  
Drought Tolerance ◽  
Total Variation ◽  
Strong Association ◽  
Principal Component ◽  
Yield Potential ◽  
High Yield ◽  
Breeding Lines ◽  
Barley Landraces ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Barley cultivation for drought areas requires reliable assessment of drought tolerance variability among the breeding germplasms. Hence, 121 barley landraces, advanced breeding lines and varieties were evaluated under both moisture non-stress and stress field conditions using a lattice square (11×11) design with two replications for each set of trials. Twelve drought tolerance indices (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI and SSPI) were used based on grain yield under normal (Yp) and drought (Ys) conditions. Analysis of variance showed a significant genetic variation among genotypes for all indices with the exception of TOL and SSPI indices. Yp had a very strong association with Ys (r=0.92**) that indicates high yield potential under non-stress can predict better yield under stress conditions. Yp and Ys were positively and significantly correlated with MP, GMP, STI, YI, HM and DI indices, whereas they were negatively correlated with SSI and SDI. In principal component analysis (PCA), the first PC explained 64% of total variation with Yp, Ys, MP, GMP, STI, YI, HM and DI. The second PC explained 35.6% of the total variation and had positive correlation with SSI, TOL, SDI and SSPI. It can be concluded that MP, GMP, STI, YI, HM and DI indices with the most positive and significant correlation with yield at both non-stress and stress environments would be better indices to screen barley genotypes, although none of the indices could undoubtedly identify high yield genotypes under both conditions.

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

2013 ◽  
Vol 64 (2) ◽  
pp. 87 ◽  
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.

Geographical distribution and phenotypic diversity of wild/weedy sorghum [Sorghum bicolor (L.) Moench] in Ethiopia: implications for germplasm conservation and crop–wild gene flow

2012 ◽  
Vol 11 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Asfaw Adugna ◽  
Endashaw Bekele
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Sorghum Bicolor ◽  
Phenotypic Diversity ◽  
Diversity Index ◽  
Germplasm Conservation ◽  
Morphological Data ◽  
Transgenic Crop ◽  
Average Value ◽  
Geographical Regions

Extensive studies of genetic diversity and population structure important for conservation of wild sorghum are yet lacking in Ethiopia, the centre of origin for cultivated sorghum. To assess both genetic diversity and the probability of gene flow between wild and cultivated types, collections of wild Sorghum bicolor were made from regions in Ethiopia where wild and cultivated sorghum coexist. Morphological data were recorded in situ for both quantitative and qualitative characters from 30 populations in five diverse geographical regions and eight agroecologies. High phenotypic diversity was observed among the wild and weedy sorghum populations. The overall standardized Shannon–Weaver diversity index (H′), computed from the frequencies of all qualitative traits, ranged from 0.47 to 0.98 with an average value of 0.76. Moreover, warm semi-arid lowland (SA2) agroecologies, which contain Tigray populations, supported the highest diversity for these traits. Subspecies verticilliflorum and drummondii (the two major subspecies of wild S. bicolor) were observed in diverse habitats throughout northern and central Ethiopia. In some areas, weedy types showed domestication traits including the absence of awns and reduced seed shattering. The existence of morphologically intermediate forms indicates that gene flow between cultivated and wild forms has likely occurred. Deployment of transgenic crop sorghum, therefore, would pose a distinct risk for transgene movement into wild Ethiopian populations.

scholarly journals The Impact of Soil Erosion on Biodiversity Conservation in Isiala Ngwa North LGA, Southeastern Nigeria

2019 ◽  
Vol 11 (24) ◽  
pp. 7192
Author(s):  
Godson Chinonyerem Asuoha ◽  
Uchenna Paulinus Okafor ◽  
Philip Ogbonnia Phil-Eze ◽  
Romanus Udegbunam Ayadiuno
Keyword(s):  
Soil Erosion ◽  
Plant Species ◽  
Diversity Index ◽  
Principal Component ◽  
Diversity Indices ◽  
Group Discussions ◽  
Southeastern Nigeria ◽  
Animal Diversity ◽  
The Impact ◽  
Agro Forestry

The impact of soil erosion on the conservation of biodiversity in Isiala Ngwa North LGA, Southeastern Nigeria was examined. Data were obtained through focus group discussions and plant species enumeration. Diversity indices of plant species were derived from quadrat analysis using Shannon Wiener’s diversity index. Eighteen soil samples were collected from agricultural erosion sites in the study area and analysed in the laboratory. The results obtained were analysed using principal component analysis (PCA). The rotated component matrix of the soil properties, as well as plant and animal diversity indices from the PCA isolated three components that together explained 93.821% of the observed variation. The results show that bush clearing in the form of slash and burn, uncoordinated bush burning and harvesting of plant species are the activities that cause soil erosion in the study area. Agro-forestry, bush fallowing, reforestation and legislation on indiscriminate harvesting of plant species were recommended.

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

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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