scholarly journals The U.S. National Cotton Germplasm Collection – Its Contents, Preservation, Characterization, and Evaluation

10.5772/58386 ◽  
2014 ◽  
Author(s):  
Richard G. Percy ◽  
James E. Frelichowski ◽  
Mark D. Arnold ◽  
Todd B. Campbell ◽  
Jane K. Dever ◽  
...  
Keyword(s):  
Germplasm Collection ◽  
The U.S

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.

scholarly journals Genotyping tools and resources to assess peanut germplasm: smut-resistant landraces as a case study

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10581
Author(s):  
Alicia N. Massa ◽  
Marina Bressano ◽  
Juan H. Soave ◽  
Mario I. Buteler ◽  
Guillermo Seijo ◽  
...  
Keyword(s):  
Germplasm Collection ◽  
Snp Markers ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genotyping Platform ◽  
Global Spread ◽  
Rnase H2 ◽  
Number Of Individuals ◽  
The U.S

Peanut smut caused by Thecaphora frezii is a severe fungal disease currently endemic to Argentina and Brazil. The identification of smut resistant germplasm is crucial in view of the potential risk of a global spread. In a recent study, we reported new sources of smut resistance and demonstrated its introgression into elite peanut cultivars. Here, we revisited one of these sources (line I0322) to verify its presence in the U.S. peanut germplasm collection and to identify single nucleotide polymorphisms (SNPs) potentially associated with resistance. Five accessions of Arachis hypogaea subsp. fastigiata from the U.S. peanut collection, along with the resistant source and derived inbred lines were genotyped with a 48K SNP peanut array. A recently developed SNP genotyping platform called RNase H2 enzyme-based amplification (rhAmp) was further applied to validate selected SNPs in a larger number of individuals per accession. More than 14,000 SNPs and nine rhAmp assays confirmed the presence of a germplasm in the U.S. peanut collection that is 98.6% identical (P < 0.01, bootstrap t-test) to the resistant line I0322. We report this germplasm with accompanying genetic information, genotyping data, and diagnostic SNP markers.

scholarly journals (3) Seed Regeneration of Short-day Onion Accessions in the U.S. Collection

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 998C-998
Author(s):  
Christopher S. Cramer ◽  
Larry D. Robertson
Keyword(s):  
New Mexico ◽  
Plant Genetic Resources ◽  
Germplasm Collection ◽  
Rio Grande ◽  
State University ◽  
Short Day ◽  
New Mexico State University ◽  
Seed Supply ◽  
Seed Regeneration ◽  
The U.S

Numerous short-day onion accessions maintained at the Plant Genetic Resources Unit (PGRU) of Geneva, N.Y., were in danger of being lost from the U.S. germplasm collection due to sub-standard viability and low seed supply of those accessions. Seed regeneration of short-day onions at Geneva, N.Y., has been difficult because of improper daylengths and environmental conditions. A project was initiated in Sept. 2001 between PGRU and the onion breeding program at New Mexico State University to regenerate 75 accessions that were in the most danger of being lost from the collection. Even though germination rates were low for most accessions, plants were recovered from 72 accessions. Two accessions did not produce bulbs as it was likely they were long-day accessions. Of the remaining accessions, two accessions produced bulbs but did not produce seed. Several accessions bolted during bulb production and plants were covered with crossing cages, crosses were made, and seed was collected. Seed of 54 accessions were sent to PGRU to be incorporated back into the collection and to become available for distribution. Seventeen accessions produced less than 35 g of seed and were retained in order to produce additional seed in a second regeneration step. Some of the short-day accessions that have become available include `Amarela Globular Rio Grande', `Babosa', `Baia Performe Sintese No. 22', `Beth Alpha', `Burgundy', `California Early Red', `Dehydrator No. 5', `Early Crystal', `Eclipse L303', `Imperial 48', `New Mexico Yellow Grano', `Pusa Red', `Red Bermuda', `Red Creole', `Red Grano', `Red Patna', and `Rio Grande'.

scholarly journals Estimation of Fruit Grade Weights Based on Fruit Number and Total Fruit Weight in Cucumber

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1117-1121 ◽  
Author(s):  
Nischit V. Shetty ◽  
Todd C. Wehner
Keyword(s):  
Efficient Method ◽  
Germplasm Collection ◽  
Plant Introduction ◽  
Fruit Weight ◽  
Fruit Number ◽  
Cucumber Fruit ◽  
The U.S

In many cases, measurement of cucumber fruit weight in small research plots involves more labor and resources than just counting the number of fruit per plot. Therefore, plant breeders are interested in an efficient method for estimating fruit weight per grade (early, marketable, and cull) based on fruit number and total fruit weight. We evaluated the cucumber germplasm collection of 810 plant introduction accessions (supplied by the U.S. Dept. of Agriculture, Regional Plant Introduction Station at Ames, Iowa) along with seven check cultivars for yield. Correlations were calculated for all pairs of fruit number and fruit weight combinations for each grade. In general, the lowest correlations were observed between the fruit weight of each grade (early, marketable, and cull) and total fruit weight or number per plot. High correlations were observed for fruit weight and fruit number within each grade (early, marketable, and cull). An efficient method for estimating fruit weight per hectare of early, marketable, and cull grades is to count total, early, and cull fruit, then measure total fruit weight. Our results showed that the fruit weight of each grade (early, marketable, and cull) was best estimated using the fruit number of that grade (early, marketable, and cull) along with the total fruit weight and total fruit number.

Response of Soybean Cultivars to Bentazon, Bromoxynil, Chloroxuron, and 2,4-DB

Weed Science ◽  
1974 ◽  
Vol 22 (1) ◽  
pp. 35-41 ◽  
Author(s):  
L. M. Wax ◽  
R. L. Bernard ◽  
R. M. Hayes
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Butyric Acid ◽  
Germplasm Collection ◽  
Department Of Agriculture ◽  
Plant Introductions ◽  
Soybean Cultivars ◽  
Highly Sensitive ◽  
Commercially Important ◽  
The U.S

The response of several hundred soybean[Glycine max(L.) Merr.] cultivars to postemergence application of four herbicides was evaluated in the field, greenhouse, and growth chamber in 1970, 1971, and 1972. Postemergence application of 3.4 kg/ha of bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide] did not significantly reduce yields of the seven commercially important soybean cultivars evaluated. All entries in the regional breeding trials, Uniform Test I to IV, were relatively tolerant of postemergence applications of the herbicides at rates about double those required for weed control. The observed order of phytotoxicity was 3.4 kg/ha of bentazon < 3.4 kg/ha of chloroxuron [3-[p-(p-chlorophenoxy)phenyl]-1,1-dimethylurea] < 0.3 kg/ha of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) = 0.4 kg/ha of 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid]. Of the 338 named U.S. and Canadian cultivars in the U.S. Department of Agriculture soybean germplasm collection, all but one were tolerant to a postemergence application of 3.4 kg/ha bentazon. One U.S. cultivar, ‘Hurrelbrink,’ and ten plant introductions from Japan were highly sensitive to bentazon. These 11 cultivars were also highly sensitive to bromoxynil and 2,4-DB and somewhat sensitive to chloroxuron.

Geographical Distribution of Genetic Diversity in Arachis hypogaea

2001 ◽  
Vol 28 (2) ◽  
pp. 80-84 ◽  
Author(s):  
C. C. Holbrook ◽  
T. G. Isleib
Keyword(s):  
Disease Resistance ◽  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Germplasm Collection ◽  
Cercospora Arachidicola ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Arachis Hypogaea L ◽  
Race 1 ◽  
The U.S

Abstract The U.S. maintains a large (&gt; 8000 accessions) and genetically diverse collection of peanut (Arachis hypogaea L.) germplasm. It is costly to screen all accessions within this collection for traits that could be useful in cultivar development. The objective of this research was to identify countries of origin that are rich sources of resistance to important peanut diseases. This would allow peanut breeders to focus their efforts on smaller subsets of the germplasm collection. Accessions in the peanut core collection were evaluated for resistance to late (Cercosporidium personatum Berk. & M. A. Curtis) and early (Cercospora arachidicola Hori) leaf spot, tomato spotted wilt Tospovirus (TSWV), the peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1], and Cylindrocladium black rot (CBR)[Cylindrocladium crotalarie (Loos) Bell & Sobers]. These data then were examined to determine if genes for resistance clustered geographically. Several geographical areas that appear to be rich sources for disease-resistant genes were identified. China had a relatively large number of accessions with resistance to the peanut root-knot nematode. Peru appeared to be a rich source of material with resistance to CBR. Resistance to late leaf spot was more frequent than expected in accessions from Bolivia and Ecuador. Bolivia was also a valuable source of resistance to early leaf spot. Early leaf spot resistance also was more prevalent than expected in accessions from India, Nigeria, and Sudan. India, Israel, and Sudan were valuable origins for material with resistance to TSWV. Accessions with multiple disease resistance were most common in India, Mozambique, and Senegal. This information should enable plant breeders to utilize more efficiently the genes for disease resistance that are available in the U.S. germplasm collection.

scholarly journals Evaluation of a Core of the U.S. Capsicum Germplasm Collection for Reaction to the Northern Root-knot Nematode

HortScience ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 805-810 ◽  
Author(s):  
Judy A. Thies ◽  
Richard L. Fery
Keyword(s):  
Germplasm Collection ◽  
The United States ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Temperate Region ◽  
The Core ◽  
The World ◽  
Gall Index ◽  
The U.S ◽  
Greenhouse Tests

Several species of root-knot nematodes [Meloidogyne incognita (Kofoid & White) Chitwood, M. arenaria (Neal) Chitwood, M. javanica (Treub) Chitwood, and M. hapla Chitwood] are major pests of peppers (Capsicum spp.) in the United States and worldwide. Resistance to M. incognita, M. arenaria, and M. javanica has been identified in several Capsicum accessions, but there are few reports of resistance to M. hapla. Therefore, we selected a 10% core (440 accessions) of the 14 available Capsicum spp. in the Capsicum germplasm collection (3,731 accessions) maintained by the U.S. Dept. of Agriculture (USDA), and evaluated this core for resistance to M. hapla in unreplicated greenhouse tests. The 11 best (most resistant) and the 3 worst (most susceptible) accessions identified in these unreplicated tests were re-evaluated in a replicated greenhouse test. Seven of these 11 “best” accessions (PI 357613, PI 357503, PI 439381, PI 297493, PI 430490, PI 267729, and PI 441676) exhibited root gall severity indices <5.0 (1 = no galls; 9 = more than 80% of the root system covered with galls) in the replicated test, and each of these indices was significantly lower than the indices of the “worst” accessions and susceptible controls. Although a gall index <5.0 indicates a moderate level of resistance, more than 3000 M. hapla eggs were extracted per gram of fresh root tissue and the reproductive index was >1.0 for each of these accessions. These observations suggest that the most resistant accessions tested are somewhat susceptible to M. hapla. The results of our evaluation of a core of the USDA Capsicum germplasm collection demonstrates clearly that there is significant genetic variability within the overall collection for M. hapla resistance. Additionally, these results identify portions of the collection where future evaluations for M. hapla resistance should be focused. For example, the origin of the two most promising C. annuum accessions (PI 357613 and PI 357503) in the core was Yugoslavia. Thus, additional accessions from this temperate region of the world should receive priority attention in any effort to identify better sources of resistance in C. annuum to M. hapla.

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