Evaluation of Ethiopian chickpea landraces for tolerance to drought

Ethiopia is a secondary center of diversity for chickpea.It is possible that these germplasm lines have developed certain degrees ofadaptation to drought during many centuries of cultivation on residual soilmoisture. We, therefore, evaluated 482 genotypes of chickpea collected fromdifferent regions of Ethiopia for their tolerance to drought at Alem Tena, adrought-prone site. Differences were observed among genotypes in their reactionsto drought and 18 tolerant genotypes were identified based on drought responseindex (DRI). These were in the top 10% yielding genotypes under drought stress.The drought susceptible check Mariye gave grain yields of only 348kg/ha. Two of the drought tolerant genotypes ACC41235 and ACC 209025 were further evaluated in pots alongwith Mariye under stressed and nonstressed moisture regimes.Unlike Mariye the two test genotypes had relatively smallerindividual leaf area, which was further reduced under low moisture stresstreatment. On the other hand, dry root weight, root volume and rooting depthdecreased significantly under low moisture stress only forMariye. It appears that reduced water loss from the plant andextensive extraction of soil moisture are factors involved in the adaptation ofEthiopian chickpeas to drought conditions. The combined effect of the twofactors enables the plant to maintain high water status.     

Genetic diversity in cucumber (Cucumis sativus L.): II. An evaluation of selected cultivars released between 1846 and 1978

Genetic variation among 155 U.S. modern and heirloom cultivars was assessed from assays of 21 polymorphic isozyme loci. Four loci (Fdp-1, Mdh-1, Mpi-1 and Pgd-1) were monomorphic. Multivariate analyses partitioned cultivars into two distinct groups: those released before 1968, and those released after 1968. Cluster analysis produced a dendrogram with 14 nodes and 28 groups. Modern U.S. and European cultivars released after 1968 differed in isozyme frequencies. Isozymic profiles clearly discriminated some cultivars with unique attributes and/or pedigrees [e.g., Windermoor Wonder (USA), Gergana (The Netherlands), Seiram (The Netherlands), Fancy Pak (USA), Dasher 2 (USA), and WI 2757 (USA)].     

AFLP fingerprinting in hop: analysis of the genetic variability of the Tettnang variety

Hops are mostly grown as an ingredient for beer production where quality and aroma properties play an important role. Tett­nanger is one of the famous aroma varieties, that had been considered to be an old landrace. As its genetic origin was unknown, the level of genetic variability was assessed by AFLP fingerprints. A representative sample of 279 individual Tett­nanger plants was analyzed by a set of six primer combinations, which had previously been proven to reveal a high level of polymorphism. Very little polymorphism was detected among the samples from Tettnang. By comparing Tett­nanger to 16 related hop varieties, which could be clearly distinguished from each other by AFLP fingerprints, two individual plants from Tett­nanger were identified to belong to the varieties Hallertauer mfr. or Backa, respectively. One further plant was considered to be a mutant of Tett­nanger. It was concluded that the variety Tett­nanger constitutes one clone. The robustness of the AFLP technique was demonstrated by using hop DNA from leaves, cones, and pellets. Except for pellets all sources of plant material yielded DNA for highly reproducible, informative AFLP-banding patterns. Our results showed, that the AFLP technique was a feasible tool for determining the level of genetic variability within one hop variety and between varieties.     

Evaluation of ‘di Romagna’ and ‘Frenchgrey’ shallots for quality characters connected to bulb colourand volatile oil content and composition

Local landraces of shallot from the Romagna region(Northern Italy) and North-western France, called Scalogno di Romagna and French grey,respectively, have recently been evaluated for morphological,biochemical and molecular characters. These populations appeared very different from common shallots and onions, so were re-classified as Allium oschaninii O.Fedtsch., whereas almost no variability was observed within these types. Four di Romagna and three French accessions were grown in Italy, and further evaluated for quality characters such asbulb colour and volatile oil content and composition. Colour was measured by means of a tristimulus colorimeter. Volatile oil was extracted by hydrodistillation and its components separated and identified by GC/MS. Colour parameters differentiated thedi Romagna from the French greyaccessions. Essential oil composition differed from what has been reported for most other Alliums, by a lower amount of1-propenyl- substituents. No individual oil component allowed a good differentiation of the two geographic origins.However, the French and di Romagna accessions were perfectly separated by the discriminant analysis of oil composition.Minor 1-propenyl- components seemed more critical for discrimination. The shallot types examined seemed biochemically differentiatedfrom Allium cepa. Variation in the examined quality characters was detected both between the two provenances and among the accessions of common geographic origin.     

The Cuban homegarden ‘conuco’: a perspective environment for evolution and in situ conservation of plant genetic resources

Summary Cuban homegardens are called conucos. On the basis of new case studies additional information is provided about these conucos, their history, composition and importance. They and other gardens of similar type are characterized as suitable environment for in situ conservation and for the continuation of evolutionary processes.     

Reduction of duplication in a Brassica oleracea germplasm collection

Summary To reduce the number of accessions in the Brassica oleracea collection of the Centre for Genetic Resources The Netherlands (CGN) groups of accessions were bulked. Accessions in a group were selections from the same landrace or old variety, and were chosen, with the help of crop experts, on the basis of their history and morphology. Since this approach was received rather sceptically in the genebank community, a genetical analysis of some of the groups and their components (named varieties) was made to justify the procedures. A selection of white cabbage and Brussels sprouts, representing two crop types of B. oleracea, was made: eleven white cabbage groups comprising 43 components, and nine Brussels sprouts groups comprising 24 components. Each group and all of its components were described on the basis of electrophoresis of nine isoenzymes on 30 plants. Most components were rightly classified; 16 percent were misclassified. All these misclassifications were within similar groups. It could be concluded that pooling of the components included in this study was justified. In two cases the isozymic patterns suggested that the groups could even have been larger. Only in the case of the two groups of Brussels sprouts Bedfordshire this was a real option. In the other case involving the white cabbage groups Langedijker Bewaar Gewoon, Langedijker Bewaar Graag and Late Herfstdeen this was not an option since these landraces, although having a common genetic background, clearly have a distinct identity as defined by morphology and history. Editorial footnote: We will encourage the publication of further results of research programs in our journal referring to such often controversially discussed concepts, and would appreciate if collections of crops with different breeding systems could be analysed in this respect.     

Genetic diversity in the Olive tree (Olea europaea L. subsp. europaea) cultivated in Portugal revealed by RAPD and ISSR markers

To assess the genetic diversity of the most important olive cultivars used in Portugal, a base collection was established with two hundred and one accessions of eleven cultivars from the different agro-ecological-regions (AER) of olive oil production. Inter-cultivar diversity was evaluated using seven RAPD primers producing fifty-nine polymorphic markers that enable cultivar distinction. Discriminant analysis according to fruit use and AER revealed a genetic structure associated with local selection both for fruit exploitation and agro-ecological adaptation. Intra-cultivar diversity of the ancient cultivar Galega was also investigated. Three RAPD and five ISSR primers produced ninety-three polymorphic markers upon seventy-seven accessions from five AERs. Total accession discrimination was achieved. UPGMA clustering and discriminant analysis revealed that the genetic diversity was predominantly structured according to accessions origin. The within and among AER variation revealed by AMOVA supported this genetic structure and showed a high proportion of intra-AER variability. These evidences suggest that Galega is composed by a mixture of different genotypes adapted to local conditions, indicating that this cultivar is in an early stage of domestication and should be treated as a landrace instead of a uniform cultivar. The assessment of Galega genetic diversity within each of the five AERs indicated the highest significant level (H_g = 6.23 at p< 0.001) in Ribatejo-Santarém. This finding associated with the distinctiveness of Galega in relation to other Portuguese cultivars and with the recent insights of olive tree domestication allowed us to hypothesize that Ribatejo-Santarém was the ecological region of origin and dispersion of this ancient cultivar.     

Response of A-genome cotton germplasm to the seedling disease pathogens,Rhizoctonia solani and Pythium ultimum

Summary Approximately two hundred A-genome cotton (Gossypium arboreum L. and G. herbaceum L.) accessions were evaluated for resistance to the seedling disease pathogens Rhizoctonia solani Kühn [Thanatephorus cucumeris (A. B. Frank) Donk], and Pythium ultimum Trow. Susceptibility rating was based on a scale of 1 to 6 where 1 = no symptoms and 6 = dead. Variation was found among A-genome accessions in response to R. solani and P. ultimum, but none were highly resistant to these pathogens. As a group, the A-genome cottons were more susceptible to the pathogens than the G. hirsutum control.Abbreviations STV-A G. hirsutum Stoneville 506 with agar only - STV-NP G. hirsutum Stoneville 506 with non-pathogenic isolate - STV-P G. hirsutum Stoneville 506 with pathogenic isolate - A₁ G. herbaceum - A₂ G. arboreum - GRIN Genetic Resources Information Network     

Host-plant resistance to Pseudomonas solanacearum in tomato germplasm

Seedlings of two hundred and thirty-three accessions of the tomato collection maintained at the Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba, Costa Rica (CATIE) and 7 cultivars used as controls were evaluated for host-plant resistance to 4 virulent strains of Pseudomonas solanacearum representing race 1 biovars 1 and 3. In general, biovar 3 strains wilted seedlings faster than biovar 1 strains but, after 20 days post-inoculation, no significant differences were noted in susceptible control ratings. Significant differences for disease index were noted, but no line with complete resistance was found. For the USA biovar 1 strain UW-25, only 5 accessions, CATIE 17331, 17334, 17349, 17739, 17740, and 2 of the control cultivars, Hawaii 7998 and UC-82B showed some degree of resistance. Conversely, both the frequency and the degree of resistance were high for Costa Rican biovar 1 strain UW-256. For biovar 3, the Costa Rican strain UW-255 was more virulent than the Peruvian strain UW-130. Eight CATIE accessions, 5539, 17331, 17333, 17334, 17345, 17349, 17742, and MIP-CH1, were as resistant as the resistant control Hawaii 7998 to 3 strains and accession 17740 was as resistant as Hawaii 7998 to all 4 strains.Journal Paper No. J-16011 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project 3123.     

Isozyme variation in some races of maize from Argentina

Summary Forty one populations of sixteen Argentine races of maize were studied with electrophoretic techniques. Seven isozyme systems coded by fifteen gene loci were used for studying the genetic variability within and among races and populations. In the whole sample was found that the variation within populations represented 78% of the isozymic variability, the variation among races was 14% while the variation among populations within races was only 8%. Cluster analysis and Principal Component analysis indicated that most races were closely related. Cateto Amarillo, Cravo and Perla Mediano were the most distinctive of the Argentine races.Germplasm Paper no. 10     

Die Gaterslebener Mutanten der Saatgerste in Beziehung zur Formenmannigfaltigkeit der ArtHordeum vulgare L. s. l. II

Zusammenfassung 49 röntgeninduzierte Mutanten der Wintergerstensorten Friedrichswerther Berg, Peragis Mittelfrühe II, Kleinwanzlebener 12 und Mahndorfer werden morphologisch beschrieben. Sie werden unter der Rangstufe Linie (auf dem gleichen Rang wie die Sorte), zusammengefaßt nach Hauptmerkmalen, in das morphologische System eingeordnet. Sie konnten 10 verschiedenen Varietäten der convar.hexastichon (L.) Alef. s. l. zugeordnet werden. Eine dieser Varietäten (var.semiaristatum, p. 240) stellt eine neue Merkmalskombination dar und wird beschrieben.Soweit bisher Kreuzungsanalysen vorliegen, werden Angaben über die Vererbung des Hauptmerkmals bei den einzelnen Mutanten gemacht; in der Regel liegen monogen rezessive Erbgänge vor. Drei verschiedene Ausprägungsgrade des Hauptmerkmals Grannen kurz und brüchig konnten auf ebenso viele Glieder einer Serie multipler Allele zurückgeführt werden (S. 235 ff). Sie werden wie folgt benannt:fragilis ^exigua ,fragilis ^mediocris ,fragilis ^distimeta . Nach der Dominanz geordnet, ergibt sich die ReiheFra > fra ^ex > fra ^med > fra ^dis .     

Chromosomal interchanges and phylogeny of some accessions of Triticum aestivum subsp. spelta

Summary The occurrence of chromosomal interchanges was studied in F1 hyrids in two diallel schemes, including nine accessions of Triticum aestivum subsp. spelta, originating from Iran, Europe and North Africa, and the common wheat variety Chinese Spring as a reference. Seven accessions of subsp. spelta differed in one translocation from Chinese Spring. The European accession Grey differed in one or perhaps two interchanges from the reference variety, and Iran 417a showed a difference of three interchanges with Chinese Spring. In total six or perhaps seven interchanges were observed. Thus the number of translocation events in subsp. spelta appeared to be low. One translocation was unique and occurred only in the accession from North Africa. Also one accession from Europe, the landrace Schwarzwald, possibly carried a unique translocation. In both diallels an interchange with a relatively low coefficient of multivalent realisation at first meiotic metaphase was observed in most accessions. The two extra translocations in Iran 417a are considered to be the result of more recent translocation events, whereas the possible second translocation in accession Grey showed such a low coefficient of multivalent realisation that its existence could be doubted.     

Die Gaterslebener Mutanten der Saatgerste in Beziehung zur Formenmannigfaltigkeit der ArtHordeum vulgare L. s. l. I

Zusammenfassung Es werden 75 röntgeninduzierte Mutanten der Sommergerstensorten Donaria und Haisa morphologisch beschrieben. Sie werden unter der Rangstufe Linie (auf dem gleichen Rang wie die Sorte), zusammengefaßt nach Hauptmerkmalen, in das morphologische System eingeordnet. 71 dieser Mutantenlinien konnten 17 verschiedenen Varietäten (4 Convarietäten) zugeordnet werden. Zwei dieser Varietäten (var.calcaratum, p. 144; var.heteroglumatum p. 152) stellen neue Merkmalskombinationen dar und werden beschrieben. Bei den restlichen 4 Mutantenlinien stieß die Einordnung auf Schwierigkeiten, ihre Stellung bleibt vorläufig offen.     

The ‘Bavarian Turnip’ — a rediscovered local vegetable variety of <Emphasis Type="Italic">Brassica rapa</Emphasis> L. em. Metzg. var. <Emphasis Type="Italic">rapa</Emphasis>

The Bavarian Turnip (Bayerische Rübe, Brassica rapa L. em. Metzg. var. rapa) is a nearly lost crop today. Until 1900, this local variety was commonly grown in Bavaria for human consumption. The special and very distinct characters of this variety in comparison with recent breeds are preferred by the farmers families and assured the persistence and survival of this turnip in situ (on farm). In the region of Dachau and Freising, located north of Munich, only four farms are known, where this old crop is still grown and maintained. Urgent measures have to be taken to safe this cultural relict for future generations.     

Promising apricot genetic resources from the Lake Van Region

This study was conducted in order to select valuable genetic resources(Prunus armeniaca L.) of apricot in Geva situatedon Lake Van Region (East Anatolia) of Turkey during 1998 and 1999. Allpopulation consisted of native apricot genotypes were examined with respect tofruit and tree characteristics for two years, and twenty-eight genotypes wereselected for future breeding efforts. Their flowering habit and desirable fruitcharacteristics were determined in comparison withHachalilolu. All selected apricots grown at 1700m in the region were not affected by late spring frosts. In themajority of genotypes, bud break, first flowering, full flowering and end offlowering occurred a few days earlier than the cultivarHachalilolu in both years, whereas, harvest waslater than that. Some selections produced larger fruits thanHachalilolu. All genotypes showed a range of25–48 g for fruit weight, 11–21% for soluble solids and0.19–2.90% for acidity. Soluble solids content was more than 20% in threeselections (G12, G29 and G33), and the acidity was lower than 1% in fivegenotypes (G2, G12, G27, G29 and G33). Selections with attractive fruit colorshad small to medium-sized fruits. Many genotypes were evaluated as promising forfurther breeding efforts.     

Genetic diversity of Musa diploid and triploid accessions from the Brazilian banana breeding program estimated by microsatellite markers

Banana (Musa spp.) is one of the most consumed fruits worldwide. Production is based mainly on triploid cultivars, and most genetic improvement programs aim to generate tetraploid hybrids obtained from the crossing of established triploid cultivars with a diploid parent genotype, improved or wild, exhibiting the trait of interest, normally resistance to biotic factors. Microsatellites were used to investigate the genetic variability and relationships between 58 Musa genotypes, including 49 diploids and nine triploid cultivars maintained at the Musa germplasm collection of the Brazilian dessert banana breeding program. Thirty-three primer pairs developed for banana were tested, and nine amplified reproducible and discrete fragments, producing a total of 115 alleles. The average number of alleles amplified per primer was 12.8, ranging from 10 to 15. The diploid genotypes presented the largest genetic variability, demonstrated by the large number of alleles detected, and the low similarity between the clones. The phenetic analysis clustered the triploid cultivars in a separated group, with the exception of the Nanica and Gros Michel cultivars, which showed high similarity with the diploid cultivar Mambee Thu. It was not possible to separate the wild diploid genotypes from the cultivated ones, indicating a common origin of these genotypes. A high proportion of duplicated alleles and/or loci was observed for diploid and triploid genotypes. The information gathered about the similarity between diploid and triploid accessions will help to define potential crosses to maximize the recovery of the typical fruit qualities required in Brazil (AAB, Pome and Silk dessert banana).     

Characterisation of white clover populations collected from the Caucasus and high altitude regions of eastern Turkey

White clover populations collected from the Caucasus region and eastern Turkey were compared with seven white clover cultivars in a moist, lowland, highly fertile environment. The Caucasus collection came from 15 sites below 1000 m and 19 sites above 1000 m; all seven sites in Turkey were above 1000 m. The populations were generally small leaved and except for those from low altitude sites in Dagestan and Azerbaijan populations were acyanogenic. None of the collected populations were significantly higher yielding than Grassland Huia in any season. However, several populations from the Caucasus were higher yielding than Kent Wild White and similar to that of Grassland Tahora. Survival was poor with only four populations having more than 50% of plants surviving after 18 months in this environment. High altitude Caucasus populations were earlier flowering than low altitude populations, an adaptation to allow adequate seed set.There was a negative relationship between altitude of population origin and proportion of cyanogenic plants; and between altitude and both leaf size and canopy height. High incidence of no leaf mark (vv) was associated with populations from colder rather than warmer environments. Populations from sites with low rainfall were larger leaved and more upright than populations from wetter sites. Populations from severely grazed sites were less upright and less cyanogenic than populations from infrequently or nil defoliated sites.Deceased     

Evaluation of Gossypium arboreum L. Germplasm for resistance to thrips

Summary As part of a project to assess the U.S. Asiatic Cotton Germplasm Collection as a source of genes for pest resistance, forty-three accessions of Gossypium arboreum L. were evaluated for resistance to thrips. Thrips, Thysanoptera spp., are a minor, but widespread pest on cotton, G. hirsutum L. and G. barbadense L. Accessions were planted in free-choice field tests in 1988, 1989, and 1990 at the Cotton Branch Experiment Station, Marianna, Arkansas. Damage ratings, based on a scale of 0 (no damage) to 7 (severe damage), were made approximately one month after planting. Relative score was computed by dividing the rating of each accession by the rating of the reference, G. hirsutum Stoneville 506. The relative score averaged over all G. arboreum accessions by year varied with the year, but was less than 100 (relative score for Stoneville 506) in each case. When data were combined for all three years, twenty-five accessions were significantly better than Stoneville 506. Introgression of the better accessions into G. hirsutum is now in progress.Abbreviations NPGS National Plant Germplasm System - STV 506 G. hirsutum Stoneville 506     

Results of activities to maintain landraces and other material in some European countries in situ before 1945 and what we may learn from them

All three recommendations to maintain landraces in European countries, given in 1927: 1. maintenance by traditional farmers, 2. maintenance by school personnel and pupils, and 3. maintenance by small agricultural institutions, were disregarded. The present outcome: maintenance by genebanks, which often grow landraces and improved cultivars of one crop next to each other, and which often are part of a large agricultural research institute, was advised against.The above observation may be of value to those who at present advocate maintenance of landraces by traditional farmers in developing countries.It is recommended that landraces should be collected and maintained in genebanks as this will result in a partial loss of the material, whereas on farm maintenance (in situ conservation) would lead to a complete loss.