scholarly journals Simple sequence repeat (SSR)-based diversity analysis of groundnut (Arachis hypogaea L.) germplasm resistant to bacterial wilt

2007 ◽  
Vol 5 (01) ◽  
pp. 27-36 ◽  
Author(s):  
E. S. Mace ◽  
W. Yuejin ◽  
L. Boshou ◽  
H. Upadhyaya ◽  
S. Chandra ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Gene Diversity ◽  
Scaling Analysis ◽  
Sources Of Resistance ◽  
Disease Response ◽  
Arachis Hypogaea L ◽  
Resistant Lines ◽  
Breeding Programmes ◽  
Mapping Populations ◽  
Selection Of

Groundnut is one of the most important oilseed crops in the world. Bacterial wilt, caused byRalstonia solanacearumE. F. Smith, is one of the major biotic constraints to groundnut production particularly in South-East Asia and East Africa. Several sources of resistance to bacterial wilt have been identified through field screening of groundnut germplasm. The aim of the present study was to quantify the genetic diversity among selected bacterial wilt-resistant lines, in comparison with the levels of variation observable within the cultivatedA. hypogaeagene pool. Thirty-two SSR markers were used to assess the degree of molecular polymorphism between 46 selected genotypes revealing 107 alleles, of which 101 (99.4%) were polymorphic with gene diversity scores ranging from 0.103 to 0.669, averaging 0.386. Cluster and multidimensional scaling analysis revealed two distinct groups within the germplasm broadly corresponding to the two subspecies (hypogaeaandfastigiata) ofA. hypogaea. However, accessions of varietiesperuvianaandaequatorianagrouped together with the varieties from subsp.hypogaea, rather than grouping with the other varieties of subsp.fastigiata.Analysis of molecular variance (AMOVA) revealed that 15% of the total observed variation was accounted for by disease response groups. This analysis will be useful in the selection of parental genotypes for mapping populations and breeding programmes attempting to broaden the genetic base of future groundnut cultivars. In particular, this opens up significant opportunities for the development of intraspecific mapping populations that will be highly relevant to modern groundnut breeding programmes.

scholarly journals Evaluation of Corn Germplasm Accessions for Resistance to Clavibacter nebraskensis, Causal Agent of Goss’s Bacterial Wilt and Leaf Blight

Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 156-163
Author(s):  
Kelsey M. Mehl ◽  
Mark A. Mikel ◽  
Carl A. Bradley
Keyword(s):  
Bacterial Wilt ◽  
Severity Score ◽  
Field Resistance ◽  
Leaf Blight ◽  
Pedigree Information ◽  
Sources Of Resistance ◽  
Initial Field ◽  
Field Screening ◽  
Second Stage ◽  
Resistant Lines

Goss’s bacterial wilt and leaf blight of corn (Zea mays), caused by Clavibacter nebraskensis, is a reemerging disease in the Midwestern United States. From 2011 to 2013, field studies and a greenhouse study were conducted to assess the University of Illinois maize inbred collection for putative sources of resistance to Goss’s bacterial wilt and leaf blight. This inbred collection consisted of over 2,000 diverse inbred corn lines that have been collected from all over the world. An initial field screen of over 1,000 inbred lines from the collection was conducted in Urbana, IL in 2011. These lines were inoculated with a C. nebraskensis cell suspension and rated for Goss’s bacterial wilt and leaf blight severity using a 1-to-9 scale, with a score of 1 being most resistant. Means for Goss’s bacterial wilt and leaf blight ratings ranged from 1 to 8.5. The initial screen identified over 150 lines that had high levels of resistance (severity score of ≤2.5). In total, 177 lines were used in the second stage of field screening. In the second stage, average Goss’s bacterial wilt and leaf blight severity ranged from 1.1 to 7.4. Nine lines with high levels of resistance in 2011 and 2012 were advanced to the third stage of field screening. The mean Goss’s bacterial wilt and leaf blight severity rating of the resistant lines in the last stage was 1.9, while the susceptible check had a mean score of 6.4. These nine lines were also used in the greenhouse to assess whether resistance varied based on inoculating roots, stems, or leaves. Disease severity was significantly (P ≤ 0.05) less when roots were inoculated compared with both leaf and stem inoculations, which were not significantly different from each other. Lines having high levels of field resistance were also found to be resistant in greenhouse screening regardless of inoculation method. Clustering of pedigree distance of the 34 resistant lines (severity score of ≤2.5) with known pedigree information found that 21 clustered with the Lancaster heterotic family, 4 were related to the Iowa Stiff Stalk Synthetic family, and 9 did not cluster with an identifiable heterotic family. These results show that the Lancaster family is an excellent source of Goss’s wilt resistance, and that fewer sources of resistance were found in other families. The most resistant lines identified from this research are potential sources of resistance to Goss’s bacterial wilt and leaf blight, and their lineage can be used in corn breeding programs to develop resistant hybrids.

scholarly journals Selection of Bacterial Wilt-resistant Lines from Regenerated Tobacco Plants.

1994 ◽  
Vol 11 (1) ◽  
pp. 71-73
Author(s):  
Kazuyuki CHATANI ◽  
Hideyoshi TOYODA ◽  
Yoshinori MATSUDA ◽  
Seiji OUCHI
Keyword(s):  
Bacterial Wilt ◽  
Tobacco Plants ◽  
Resistant Lines ◽  
Selection Of

scholarly journals Assessing genetic diversity, allelic richness and genetic relationship among races in ICRISAT foxtail millet core collection

2012 ◽  
Vol 10 (3) ◽  
pp. 214-223 ◽  
Author(s):  
M. Vetriventhan ◽  
H. D. Upadhyaya ◽  
C. R. Anandakumar ◽  
S. Senthilvel ◽  
H. K. Parzies ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Core Collection ◽  
Expressed Sequence Tag ◽  
Foxtail Millet ◽  
Racial Classification ◽  
Germplasm Identification ◽  
Breeding Programmes ◽  
Mapping Populations ◽  
Selection Of

Foxtail millet (Setaria italica (L.) P. Beauv.) is an ideal crop for changing climate and food habits of peoples due to its short duration, high photosynthetic efficiency, nutritional richness and fair resistance to pest and diseases. However, foxtail millet yields are low mainly due to the lack of effort for its improvement and the lack of proper utilization of existing genetic variability. To enhance the use of diverse germplasm in breeding programmes, a core collection in foxtail millet consisting of 155 accessions was established. Core collection accessions were fingerprinted using 84 markers (81 simple sequence repeats (SSRs) and three Expressed Sequence Tag (EST)-SSRs). Our results showed the presence of greater molecular diversity in the foxtail millet core collection. The 84 markers detected a total of 1356 alleles with an average of 16.14 alleles (4–35) per locus. Of these, 368 were rare alleles, 906 common alleles and 82 the most frequent alleles. Sixty-one unique alleles that were specific to a particular accession and useful for germplasm identification were also detected. In this study, the genetic diversity of foxtail millet was fairly correlated well with racial classification, and the race Indica showed a greater genetic distance from the races Maxima and Moharia. The pairwise estimate of dissimilarity was >0.50 except in 123 out of 11,935 pairs which indicated a greater genetic variability. Two hundred and fifty pairs of genetically most diverse accessions were identified. This large molecular variation observed in the core collection could be utilized effectively by breeders or researchers for the selection of diverse parents for breeding cultivars and the development of mapping populations.

Sources of resistance to Fusarium wilt and root-knot nematode in indigenous chickpea germplasm

2012 ◽  
Vol 10 (3) ◽  
pp. 258-260 ◽  
Author(s):  
Mohar Singh ◽  
Z. Khan ◽  
Krishna Kumar ◽  
M. Dutta ◽  
Anju Pathania ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Rating Scale ◽  
Resistance Breeding ◽  
Practical Method ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Chickpea Wilt ◽  
Breeding Programmes ◽  
Race 1 ◽  
Moderately Resistant

Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.

scholarly journals Genetic diversity and selection of genotypes to enhance Zn and Fe content in common bean

2010 ◽  
Vol 90 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Z I Talukder ◽  
E Anderson ◽  
P N Miklas ◽  
M W Blair ◽  
J Osorno ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Common Bean ◽  
Allelic Variation ◽  
Gene Pools ◽  
Gene Sequences ◽  
Mineral Contents ◽  
Discriminatory Ability ◽  
Fe Content ◽  
Mapping Populations ◽  
Selection Of

Common bean (Phaseolus vulgaris L.) is an important source of dietary protein and minerals worldwide. Genes conditioning variability for mineral contents are not clearly understood. Our ultimate goal is to identify genes conditioning genetic variation for Zn and Fe content. To establish mapping populations for this objective, we tested mineral content of 29 common bean genotypes. Chemical analyses revealed significant genetic variability for seed Zn and Fe contents among the genotypes. Genetic diversity was evaluated with 49 primer pairs, of which 23 were simple sequence repeats (SSR), 16 were developed from tentative consensus (TC) sequences, and 10 were generated from common bean NBS-LRR gene sequences. The discriminatory ability of molecular markers for identifying allelic variation among genotypes was estimated by polymorphism information content (PIC) and the genetic diversity was measured from genetic similarities between genotypes. Primers developed from NBS-LRR gene sequences were highly polymorphic in both PIC values and number of alleles (0.82 and 5.3), followed by SSRs (0.56 and 3.0), and markers developed from TC (0.39 and 2.0). genetic similarity values between genotypes ranged from 14.0 (JaloEEP558 and DOR364) to 91.4 (MIB152 and MIB465). Cluster analysis clearly discriminated the genotypes into Mesoamerican and Andean gene pools. Common bean genotypes were selected to include in crossing to enhance seed Zn and Fe content based on genetic diversity and seed mineral contents of the genotypes. Key words: Common bean, genetic diversity, mineral nutrients, breeding

scholarly journals Analysis of measured and calculated counterpart test data in PWR and VVER 1000 simulators

2005 ◽  
Vol 20 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Francesco d’Auria ◽  
Marco Cherubini ◽  
Maria Galassi ◽  
Nikolaus Muellner
Keyword(s):  
Nuclear Power ◽  
Computer Code ◽  
Scaling Analysis ◽  
Behavior Prediction ◽  
Plant Behavior ◽  
Test Methodology ◽  
Qualitative Level ◽  
Reactor Type ◽  
New Phenomena ◽  
Selection Of

This paper presents an over view of the "scaling strategy", in particular the role played by the counter part test methodology. The recent studies dealing with a scaling analysis in light water reactor with special regard to the VVER 1000 Russian reactor type are presented to demonstrate the phenomena important for scaling. The adopted scaling approach is based on the selection of a few characteristic parameters chosen by taking into account their relevance in the behavior of the transient. The adopted computer code used is RELAP5/Mod3.3 and its accuracy has been demonstrated by qualitative and quantitative evaluation. Comparing experimental data, it was found that the investigated facilities showed similar behavior concerning the time trends, and that the same thermal hydraulic phenomena on a qualitative level could be predicted. The main results are: PSB and LOBI main parameters have similar trends. This fact is the confirmation of the validity of the adopted scaling approach and it shows that PWR and VVER reactor type behavior is very similar. No new phenomena occurred during the counter part test, despite the fact that the two facilities had a different lay out, and the already known phenomena were predicted correctly by the code. The code capability and accuracy are scale-independent. Both character is tics are necessary to permit the full scale calculation with the aim of nuclear power plant behavior prediction. .

scholarly journals New sources of resistance to bacterial wilt identified in dry bean germplasm collection

2004 ◽  
Vol 4 (1) ◽  
pp. 111-114 ◽  
Author(s):  
C.A. Rava ◽  
J.G.C. Costa ◽  
J.R. Fonseca ◽  
A.L. Salgado
Keyword(s):  
Bacterial Wilt ◽  
Germplasm Collection ◽  
Sources Of Resistance ◽  
Dry Bean

scholarly journals Selection and Inheritance of Tomato Resistance against Ralstonia solanacearum

2019 ◽  
Vol 23 (1) ◽  
pp. 61
Author(s):  
Isna Maulida ◽  
Rudi Hari Murti ◽  
Triwidodo Arwiyanto
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Dominant Gene ◽  
Tomato Plants ◽  
Breeding Lines ◽  
Back Cross ◽  
Inheritance Patterns ◽  
Randomized Design ◽  
Resistant Varieties ◽  
Resistant Lines

Ralstonia solanacearum is a plant pathogen causes wilting which is a major obstacle in the cultivation of tomato plants. In plant breeding, knowledge of the source of resistance genes and inheritance patterns is important in the development of bacterial wilt resistant varieties. This study aimed to obtain bacterial wilt resistant lines and to find out the inheritance pattern of tomato resistance to bacterial wilt. Selection of resistant plant involved the selected breeding lines from irradiation and crossing collections of the Genetic Laboratory, Faculty of Agriculture, Universitas Gadjah Mada. Introduced lines of H-7996 and F1 Permata and Timoti were used as a control. H-7996 as resistant parents and GM2 as susceptible parents, and their offspring include F1 GM2 x H-7996, F1 reciprocal, F2, Back Cross 1 (F1 x GM2), and Back Cross 2 (F1 x H-7996) used in testing inheritance patterns. Inoculation was carried out 1 week after planting by pouring 100 ml of water suspension of R. solanacarum (108  cfu/ml) on the roots. Completely Randomized Design (CRD) was used in this experiment. The scoring observation was carried out every week for one month. This study showed that Permata as a control was the most resistant, while Timoti and H-7996 were medium resistant. The CLN, G6, G8, and G7 lines were susceptible medium, yet only G8 and G7 with the smallest percentage of disease intensity and not significantly different than Timoti. The resistance gene to bacterial wilt on H-7996 was controlled by genes in the cell nucleus with additive-dominant gene action. Resistance to bacteria has a moderate level of heritability.

scholarly journals Pigeonpea composite collection and identification of germplasm for use in crop improvement programmes

2011 ◽  
Vol 9 (01) ◽  
pp. 97-108 ◽  
Author(s):  
H. D. Upadhyaya ◽  
K. N. Reddy ◽  
Shivali Sharma ◽  
R. K. Varshney ◽  
R. Bhattacharjee ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Crop Improvement ◽  
Germplasm Collection ◽  
Sources Of Resistance ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses ◽  
Mini Core Collection ◽  
Breeding Programmes ◽  
Simple Sequence ◽  
High Seed Yield

Pigeonpea (Cajanus cajan(L.) Millsp. is one of the most important legume crops as major source for proteins, minerals and vitamins, in addition to its multiple uses as food, feed, fuel, soil enricher, or soil binder, and in fencing, roofing and basket making. ICRISAT's genebank conserves 13,632 accessions of pigeonpea. The extensive use of few parents in crop improvement is contrary to the purpose of collecting a large number of germplasm accessions and has resulted in a narrow base of cultivars. ICRISAT, in collaboration with the Generation Challenge Program, has developed a composite collection of pigeonpea consisting of 1000 accessions representing the diversity of the entire germplasm collection. This included 146 accessions of mini core collection and other materials. Genotyping of the composite collection using 20 microsatellite or simple sequence repeat (SSR) markers separated wild and cultivated types in two broad groups. A reference set comprising 300 most diverse accessions has been selected based on SSR genotyping data. Phenotyping of the composite collection for 16 quantitative and 16 qualitative traits resulted in the identification of promising diverse accessions for the four important agronomic traits: early flowering (96 accessions), high number of pods (28), high 100-seed weight (88) and high seed yield/plant (49). These accessions hold potential for their utilization in pigeonpea breeding programmes to develop improved cultivars with a broad genetic base. Pigeonpea germplasm has provided sources of resistance to abiotic and biotic stresses and cytoplasmic-male sterility for utilization in breeding programmes.

Flavor Profiles of Wild Species-Derived Peanut Breeding Lines

2008 ◽  
Vol 35 (2) ◽  
pp. 81-85 ◽  
Author(s):  
S. P. Tallury ◽  
H. E. Pattee ◽  
T. G. Isleib ◽  
H. T. Stalker
Keyword(s):  
Wild Species ◽  
Interspecific Hybrid ◽  
Diploid Species ◽  
Sensory Attributes ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
Cultivated Peanut ◽  
Important Quality

Abstract Several diploid wild species of the genus Arachis L. have been used as sources of resistance to common diseases of cultivated peanut (Arachis hypogaea L.). Because flavor is among the most important quality attributes for commercial acceptance of roasted peanuts, sensory attributes of interspecific hybrid derived breeding lines were evaluated to determine if transfer of disease resistance from wild species is associated with concomitant changes in flavor. Sixteen interspecific hybrid derivatives with five diploid species in their ancestries and the commercial flavor standard, NC 7 were evaluated for sensory quality. Significant variation among entries was found for the roasted peanut, sweet, and bitter sensory attributes, but not for the overall contrast between NC 7 and the wild species-derived breeding lines. The variation was either between two groups of wild species-derived breeding lines or within one or both groups. Introduction of disease and pest resistance traits from Arachis species did not result in degradation or improvement of the flavor profile. This suggests that flavor of wild species-derived germplasm will not prevent its use either as parents in peanut breeding programs or as cultivars.

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