scholarly journals Geographical patterns of diversity for qualitative and quantitative traits in the pigeonpea germplasm collection

2005 ◽  
Vol 3 (3) ◽  
pp. 331-352 ◽  
Author(s):  
Hari D. Upadhyaya ◽  
R.P.S. Pundir ◽  
C.L.L. Gowda ◽  
K.N. Reddy ◽  
Sube Singh
Keyword(s):  
Quantitative Traits ◽  
Diversity Index ◽  
Germplasm Collection ◽  
Flower Colour ◽  
Principal Component ◽  
The Philippines ◽  
Growth Duration ◽  
Flowering Pattern ◽  
Stem Colour ◽  
Germplasm Accessions

We analysed the patterns of variation for 14 qualitative and 12 quantitative traits in 11,402 pigeonpea germplasm accessions from 54 countries, which were grouped into 11 regions. Semi-spreading growth habit, green stem colour, indeterminate flowering pattern and yellow flower colour were predominant among qualitative traits. Primary seed colour had maximum variability and orange colour followed by cream were the two most frequent seed colours in the collection. Variances for all the traits were heterogeneous among regions. The germplasm accessions from Oceania were conspicuous by short growth duration, short height, fewer branches, pods with fewer seeds, smaller seed size and lower seed yields. The accessions from Africa were of longer duration, taller, with multi-seeded pods and larger seeds. The germplasm diversity indicated by Shannon–Weaver diversity index (H′) pooled over all traits, was highest for Africa (0.464±0.039) and lowest for Oceania (0.337±0.037). The cluster analysis based on three principal component scores using 12 quantitative traits revealed formation of three clusters: cluster 1 includes accessions from Oceania; cluster 2 from India and adjacent countries; and cluster 3 from Indonesia, Thailand, the Philippines, Europe, Africa, America and the Caribbean countries. Pigeonpea-rich countries such as Myanmar, Uganda, and others like Bahamas, Burundi, Comoros, Haiti and Panama are not adequately represented in the collection, and need priority attention for germplasm exploration.

scholarly journals Multivariate analysis of quantitative traits can effectively classify rapeseed germplasm

Genetika ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 545-559 ◽  
Author(s):  
Mirjana Jankulovska ◽  
Sonja Ivanovska ◽  
Ana Marjanovic-Jeromela ◽  
Snjezana Bolaric ◽  
Ljupcho Jankuloski ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Vegetative Growth ◽  
Quantitative Traits ◽  
Principal Component ◽  
Breeding Program ◽  
Oil Yield ◽  
Growth Duration ◽  
Data Set ◽  
Combined Application ◽  
Selection Of

In this study, the use of different multivariate approaches to classify rapeseed genotypes based on quantitative traits has been presented. Tree regression analysis, PCA analysis and two-way cluster analysis were applied in order todescribe and understand the extent of genetic variability in spring rapeseed genotype by trait data. The traits which highly influenced seed and oil yield in rapeseed were successfully identified by the tree regression analysis. Principal predictor for both response variables was number of pods per plant (NP). NP and 1000 seed weight could help in the selection of high yielding genotypes. High values for both traits and oil content could lead to high oil yielding genotypes. These traits may serve as indirect selection criteria and can lead to improvement of seed and oil yield in rapeseed. Quantitative traits that explained most of the variability in the studied germplasm were classified using principal component analysis. In this data set, five PCs were identified, out of which the first three PCs explained 63% of the total variance. It helped in facilitating the choice of variables based on which the genotypes? clustering could be performed. The two-way cluster analysissimultaneously clustered genotypes and quantitative traits. The final number of clusters was determined using bootstrapping technique. This approach provided clear overview on the variability of the analyzed genotypes. The genotypes that have similar performance regarding the traits included in this study can be easily detected on the heatmap. Genotypes grouped in the clusters 1 and 8 had high values for seed and oil yield, and relatively short vegetative growth duration period and those in cluster 9, combined moderate to low values for vegetative growth duration and moderate to high seed and oil yield. These genotypes should be further exploited and implemented in the rapeseed breeding program. The combined application of these multivariate methods can assist in deciding how, and based on which traits to select the genotypes, especially in early generations, at the beginning of a breeding program.

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.

A strategy for selecting diverse accessions using Principal Component Analysis from a large germplasm collection of soybean

2003 ◽  
Vol 1 (2-3) ◽  
pp. 151-156 ◽  
Author(s):  
R. L Sapra ◽  
S. K. Lal
Keyword(s):  
Principal Component Analysis ◽  
Sample Size ◽  
Principle Component Analysis ◽  
Quantitative Traits ◽  
Germplasm Collection ◽  
Principal Component ◽  
Target Population ◽  
Component Analysis ◽  
Principle Component ◽  
The Individual

AbstractWe suggest a diversity-dependent strategy, based on Principle Component Analysis, for selecting distinct accessions/parents for breeding from a soybean germplasm collection comprising of 463 lines, characterized and evaluated for 10 qualitative and eight quantitative traits. A sample size of six accessions included all the three states, namely low, medium and high of the individual quantitative traits, while a sample of 16–19 accessions included all the 60–64 distinct states of qualitative as well as quantitative traits. Under certain assumptions, the paper also develops an expression for estimating the size of a target population for capturing maximum variability in a sample three accessions.

Variation in morphology, plant habit, proanthocyanidins, and flavonoids within a Lottus germplasm collection

2008 ◽  
Vol 88 (1) ◽  
pp. 121-132 ◽  
Author(s):  
Margaret Gruber ◽  
Birgitte Skadhauge ◽  
Min Yu ◽  
Alister Muir ◽  
Kenneth Richards
Keyword(s):  
Plant Defence ◽  
Geographic Origin ◽  
Germplasm Collection ◽  
Flower Colour ◽  
Plant Size ◽  
Collection Site ◽  
Plant Habit ◽  
Flavonoid Composition ◽  
Stem Colour ◽  
Geographical Locations

Lotus species collec ted from a range of geographical locations were evaluated for relationships between plant habit and size, leaf proanthocyanidin (PA) content, flower colour, stem colour, leaf colour, trichome density, and geographic origin. No relationships occurred between leaf PA concentration and morphological trait or collection site. Trichome coverage was moderately correlated with plant size (r = -0.70). Several accessions, e.g., L. angustissimus L. and L. castellanis Boiss. & Reut., consisted of small, trichome-covered plants distinct from the large, glabrous plants typical of the model species L. corniculatus var. japonicus ecotype Gifu B129. These two morphology types were also represented among the tan mutants of Gifu B129. Due to the importance of trichomes and PA in plant defence, PA composition was compared between L. angustissimusand tan1 (both representing the small trichome-covered phenotype) and ecotype Gifu B129 and tan2 (both representing the large, glabrous phenotype). Both the tan1 and tan2 mutants accumulated substantial amounts of leaf PA similar in size to the small oligomers recovered from leaves of L. angustissimus. PA polymers were undetectable in Gifu B129 leaves, while floral PA extracts of this ecotype included a much larger PA polymer. Flavonoid composition in leaves of tan1 and L. angustissimus was complex, and differed from the simple profile in Gifu B129 leaves. Key words: Lotus, proanthocyanidin, flavonoids, trichomes, morphology, plant habit, variability

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

Ecogeographical studies identify diversity and potential gaps in the largest germplasm collection of bladder clover (Trifolium spumosum L.)

2007 ◽  
Vol 58 (7) ◽  
pp. 728 ◽  
Author(s):  
K. Ghamkhar ◽  
R. Snowball ◽  
S. J. Bennett
Keyword(s):  
Genetic Diversity ◽  
Germplasm Collection ◽  
Principal Component ◽  
Collection Site ◽  
Plant Germplasm ◽  
Germplasm Collections ◽  
Ecological Aspects ◽  
Passport Data ◽  
Ecogeographical Diversity ◽  
Germplasm Accessions

Plant germplasm collections are important reservoirs of diversity for plant breeders and adding to the knowledge of the diversity among and within germplasm accessions helps plant breeders to use them more efficiently. The annual legume, bladder clover (Trifolium spumosum L.), was the model plant in this study. The hypothesis that ecogeographical variables are important sources of diversity in the germplasm collection of bladder clover and some variables are more important than others has been studied. Three themes have been addressed here: firstly, analysis of the existing passport data to determine a minimum set of ecogeographical descriptors required for capturing ecological aspects of each collection site; secondly, illustration of the ecogeographical regions and subregions using GIS techniques to identify areas with the greatest likelihood of filling gaps in the collection; thirdly, development of an approach for the evaluation of genetic diversity by grouping accessions with a focus on outliers within the collection using principal component and cluster analyses. In this paper the importance of longitude as a geographical factor has been documented and the overall ecogeographical diversity in the germplasm collection of bladder clover has been screened.

scholarly journals Genetic Characterization of Tunisian Lime Genotypes Using Pomological Traits

2020 ◽  
Vol 28 (1) ◽  
pp. 65-76
Author(s):  
Olfa Saddoud Debbabi ◽  
Selma Ben Abdelaali ◽  
Rym Bouhlal ◽  
Sabrine Zneidi ◽  
Nasr Ben Abdelaali ◽  
...  
Keyword(s):  
Quantitative Traits ◽  
Phenotypic Diversity ◽  
Diversity Index ◽  
Principal Component ◽  
Fruit Shape ◽  
Ex Situ ◽  
Breeding Programs ◽  
Wiener Diversity Index ◽  
On Farm

AbstractCitrus genus includes a wide number of species that have been long cultivated and well adapted in Tunisia. It is represented by small number of plantations and considered as underutilized in Tunisia. Our goal was to genetically characterize Tunisian lime genotypes to obtain data useful for gene conservation and breeding purposes. The survey of genotypes was conducted in the Cap Bon region, where citrus cultivation is the most spread. Sixteen quantitative and 19 qualitative parameters were evaluated. The observed accessions belonged to three different species: Citrus limetta, Citrus latifolia (limes Byrsa), and Citrus limettioides (limes of Palestine) according to Tanaka classification. Principal component analysis confirmed these classifications. Four-cell analysis (FCA) was used to determine the most threatened genotypes. Quantitative traits were evaluated and allowed the discrimination between genotypes. Many quantitative traits of fruit and juice were highly positively and significantly correlated. Phenotypic diversity was determined using Shannon–Wiener diversity index (H’). The highest value of diversity index was observed for both vesicle thickness and thickness of segment walls (H’ = 0.98). Intermediate values were observed for both fruit axis (H’= 0.49) and pulp firmness (H’ = 0.43). However, fruit shape (H’ = 0.24), shape of fruit apex (H’ = 0.24), and vesicle length (H’ = 0.33) presented the lowest values of diversity index. Current findings will be useful to conserve threatened genotypes ex situ and on farm and also will guide strategic conservation on Citrus genetic resources for future breeding programs.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

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