Plant Pathology Commons^™

The Role Of Selfing In The Breeding Of Lolium Italicum, P Rotili, C Scotti, M Romani

IGC Proceedings (1977-2023)

In the irrigated plains of Lombardy (Italy) permanent meadows are continuously eliminated and replaced with maize. This imposes the collection and conservation of Lolium italicum and other species typical of these meadows (dactylis, bromus spp. etc.). Many expeditions were made by the Forage Crops Institute of Lodi, together with English colleagues as well as colleagues from Belgium, Holland, Japan and France. At pre­sent, Lolium italicum is extensively used as catch crop, sown in autumn and harvested in spring, before sowing maize. But we consider this plant useful for artificial meadows, able to give a full production for two years …

The Effect Of Selfing On Trifolium Alexandrinum Measured In Conditions Of Interference Among The Plants, P Rotili, G Gnocchi

IGC Proceedings (1977-2023)

After the constitution of the cv Sacromonte the breeding work on berseem (Trifolium alexandrinum) at the Forage Crop Institute of Lodi was slowed. A renewed interest in nitrogen fixing legumes in recent years has led to a program aimed at reevaluating the berseem clover. Today this crop is utilized not only in South Italy (autumn sowing) but in North Italy as well and in some Central European countries (spring sowing). The greatest utilization is in Egypt where berseem is grown either for forage crop or for green manure crop, usually preceding cotton or summer vegetables.

Analysis Of Variation In Sainfoin (Onobrychis Viciifolia) By Clustering, J A. Fortune

IGC Proceedings (1977-2023)

Sainfoin (Onobrychis viciifolia) is a forage legume that attracts interest due to its feeding value to ruminants. This is based on factors such as hight voluntary intake, non-bloating and protein protection, all of which appear related to the con­centration of condensed tannins in the plant tissue (Ulyatt et al., 1977). Agronomic difficulties with sainfoin such as low yield and poor persitence show a lack of consistency between experiments which seem to be due, in part, to the level of het­erogeneity displayed by the available sainfoin cultivars and germplasm (Fortune and Withers, 1980; Rumball, 1982). By permitting examination of the …

Recurrent Selection And Hydroponic Cultures For Improving The Efficiency Of Forage Grass Breeding, A.P M. Den Nijs, A.H C.M Schapendonk

IGC Proceedings (1977-2023)

The largest constraint in breeding temperate grasses is the efficiency of selection. This is related to the complex combi­nation of desired characters which ensures persisting pro­ductivity. Selection usually starts with spaced plants, later fol­lowed by progeny tests in sown swards. The applicability of selection among spaced plants for characters to be expressed under heavy competition in the grass sward has often been deb­ated. A solution to this problem is growing spaced plants under competitive conditions provided by a sward of a distinguish­able grass species (Van Dijk and Winkelhorst, 1978). Recurrent selection of slightly inbred populations of perennial ryegrass via this …

Great Diversity For Increased Yield Within Narrow Grass Population, Glenn W. Burton

IGC Proceedings (1977-2023)

Increasing yield of animal product per unit of input is the ultimate objective of any forage breeding project. It increases the efficiency of production and the profit of the producer. It may be achieved by screening and utilizing the world diversity of a species as has been demonstrated in Cynodon spp. (Burton, 1947, 1988). It can also be realized by recurrent restricted phenotypic selection (RRPS) within a narrow-based grass pop­ulation. Pensacola bahiagrass, Paspalum notatum var. saure Parodi, a sexual diploid (2n = 20) that occupies several million hectares in the southern USA is such a grass. It originated as a …

Recurrent Selection Of White Clover (Trifolium Repens L.) Using Self-Compatibility Factor, T Yamada, S Higuchi, H Fukuoka

IGC Proceedings (1977-2023)

White clover (Trifolium repens L.) is a very important forage legume in temperate grasslands. Mass selection, maternal line selection and synthetics are used in most cases of white clover breeding. Usually these breeding methods are cyclical schemes of selection by which frequencies of favorable genes are increased in the population, and such selections represent recurrent selection in its broadest sense (Hallauer, 1981). How­ever, in a narrow sense it seems that a recurrent selection pro­cedure, by which parents of superior families or strains are maintained by means of lines, is more promising for the improvement of outcrossing species. The greatest …

Mise Au Point De Techniques D’Electrophorese D’Enzymes Et De Proteines Pur L’Etude Du Polymorphisme D’Especes Spontanees Annuelles De Medicago, F Zhora Fyad-Lameche

IGC Proceedings (1977-2023)

Ce-travail s'inscrit dans le cadre d'une etude plus vaste, qui a pour but !'exploitation des Medicago annuels, menee par l'I.D.G.C. qui organise a cet effet depuis plusieurs annees, un programme de prospection et de collection de ces especes. Ce materiel, destine a une utilisation accrue en agronomie, neces­site une etude genetique. Dans cette perspective, ii fut decide d'utiliser le polymor­phisme enzymatique et proteique pour l'etude du systeme de reproduction, !'evaluation de la variabilite et l'identificatiQn de differents ecotypes. Dans cette note sont decrites !es conditions techniques opti­males pour !'analyse par electrophorese de differents systemes enzymatiques et des proteines totales et …

Selection Of Paspalum Spp. Adapted To Seasonally Flooded Varzea Lands In Central Brazil, B Grof, R P. De Andrade, M A. De Souza, J.M F. Valls

IGC Proceedings (1977-2023)

Seasonally flooded lands with a high water table (varzea) constitute a significant portion of the Cerrados. It is estimated that there are 30 x 106 ha of hydromorphic soils in Brazil and 12 x 106 ha of these varzea lands are situated in the Cerrados (Goedert, 1986). Paspalum is a predominantly American genus, it contains c. 250 species, most of which are good grazing grasses and several of which are adapted to wet situations. According to Chase (1944), the majority of the c. 160 species of this genus occurring in Brazil are well-accepted by cattle. A major limitation to the …

Forage Germplasm Resources For The Mediterranean And Adjacent Arid/Semi-Arid Areas, R Reid, J Konopka, P M. Perret, L Guarino

IGC Proceedings (1977-2023)

The mandate of IBPGR is to further the study, collection, documentation, evaluation and utilization of the genetic diver­sity of useful plants for the benefit of people throughout the world. Between 1974, when IBPGR was established as an autonomous centre in the CGIAR system, and 1988, IBPGR has been responsible for ensuring the collection and conser­vation of significant genetic resources to the world's germplasm collections.

Perennial Ryegrass From Temperate South Europe, H S. Easton, G Charmet, M B. Forde, J A. Oliveira, K H. Widdup, E M. Cooper, A Bion, F Balfourier

IGC Proceedings (1977-2023)

Material from Mediterranean latitudes has been used in New Zealand breeding programmes to improve cool season growth potential (Barclay, 1960; Rumball, 1982). To augment the material available for use in breeding programmes in New Zealand, Spain and France, seed was collected from old pasture in south Spain, coastal and inland Portugal, northwest Spain, central and north Italy (Forde and Easton, 1986). This paper gives results of 68 field collected samples of peren­nial ryegrass (Lolium perenne L.) from the above regions grown in New Zealand in comparison with control cultivars and for 94 samples from northwest Spain grown in France …

Overall Quality And Quantity Evaluations Of Native Ecotypes Of Crested Wheatgrasses Of Iran, B Peymani-Fard

IGC Proceedings (1977-2023)

Agropyron cristatum (L.) Gaertn (crested wheatgrass) is indigenous to central Asia including parts of the USSR, China, Afghanistan, Turkey and Iran (Bore, 1970). It is a perennial tufted grass which often grows naturally on stony slopes and calcareous soils. In very hot dry periods it tends to remain dor­mant but renews its growth as soon as its moisture supply returns to normal. It also survives the coldest temperature encountered in its area of adaptation (Rogler, 1960). The toler­ance of Agropyron cristatum to heavy spring grazing results from early root activity, early accumulation of leaf tissue and significant accumulation of carbohydrates …

Evaluation Of Local Annual Medic Ecotypes In Morocco, M Tazi, A Oulahboub, B Lahsini, M Laadnani, R Kouriri

IGC Proceedings (1977-2023)

The self regenerating annual pasture legumes are used in rotation with cereals in the so called ley farming-system laun­ched by the Ministry of Agriculture and Agrarian Reform for improving the production of some 1,375,000 hectares of fallow lands in Morocco (Tazi et al., 1987). There have been several attempts of introducing annual medics (Medicago sp.) in North Africa and West Asia but with little success, one of the reasons being the lack of adapted cultivars (Cocks, 1985 and Francis, 1987). In Morocco, native annual medics can play an important role in providing germplasm for selecting cultivars suitable for local …

Contribution A L’Etude Des Especies Spontanees Du Genre Trifolium L. En Algerie: Repartition En Fonction De Quelques Facturs Du Milieu, M Zatout, R Berrekia, A Abdelguerfi

IGC Proceedings (1977-2023)

En Algerie, le deficit chronique en lait et viande est du essen­tiellement a une mauvaise alimentation du troupeau. Les four­rages cultives occupent une faible superficie par rapport a !'en­semble des cultures herbacees et l'essentiel de l'alimentation du cheptel repose sur Jes jacheres et Jes parcours. Le genre Trifolium, sur lequel s'est porte notre inten��t, com­porte plusieurs especes spontanees dont le role fourrager est certain. Cependant, ii est indispensable, comme cela a ete fait pour Jes genres Medicago, Scorpiurus et Hedysarum, de definir Ia repartition des differentes especes de ce genre en fonction des facteurs du milieu. Ceci constitue le but …

Screening Of 2n Gametes To Produce New Tetraploid Material From Diploids In Dactylis Glomerata L., Roselyne Lumaret, N Maceira, Anita De Haan, J Delay

IGC Proceedings (1977-2023)

The Dactylis glomerata L. autopolyploid complex is very diverse and includes at least 15 diploid (2n = 2X = 14), 3 main natural tetraploid (2n = 4X = 28) and one hexaploid subspecies (2n = 6x = 42), each having a distinct phenotype and geographical distribution. The diploids are generally each confined to a single habitat (Borrill, 1978 ; Lumaret, 1988). In contrast, the three major 4X subspecies are generally distributed over a wide range of habitats and are favoured by man's activity (cultivation). Where there is considerable inter­penetration of several types of climate, these 4X types may be connected …

Morphological Studies As A Tool For The Evaluation Of Wide Tropical Forage Grass Germplasms, J.C G. Costa, Y H. Savidan, L Jank, L.H R. Castro

IGC Proceedings (1977-2023)

After many experiments of introduction and evaluation of tropical forage grasses, it is known nowadays, which genera and species produce well and show adaptation to the specific soil and climatic conditions of the different regions of Brazil. One of the widely used species especially for finishing cattle, is P. maximum Jacq.

The Brazilian agricultural research corporation (EMBRAPA) introduced germplasm of P. maximum from Africa, in an attempt to bring variability into the country, aiming at selection and release of new, more productive culti­vars, therefore increasing pasture diversification. This introduced P. maximum germplasm was collected by Orstom (Combes and Pernes, 1970) …

Pasture Diversification Through Selection Of New Panicum Maximum Cultivars In Brazil, L Jank, Y H. Savidan, J.C G. Costa, C B. Do Valle

IGC Proceedings (1977-2023)

Cattle rearing in Brazil depends almost exclusively on pastures, of which, 35 % consist of cultivated introduced species. Guineagrass, Panicum maximum Jacq. is the main introduced forage grass species in cattle finishing, because of its ease of propagation, fast establishment after sowing and rapid and abundant growth of high quality forage during the rainy season. About 10 cultivars are commercialized in the country, the most important being « Coloniao » : a tall, tufted perennial plant (up to 3.5 m) with erect stems and long leaves (up to 1.0 m). It presents management problems however ; when allowed to grow …

Contribution A L’Etude Des Especes Spontanees Du Genre Trifolium L. En Algerie Variabilite Au Niveau Des Graines Et Des Infrutescences Chez 17 Populations De T. Angustifolium L., A Ghoubay, A Abdelguergi

IGC Proceedings (1977-2023)

En Algerie, le genre Trifolium L. comprend un grand nombre d'especes; Quezel et Santa (1962) en ont decrit 36. Ce genre par la tres grande diversite de ses especes peut jouer un role impor­ tant dans la mise en valeur des terres et la diversification des productions fourrageres. Dans le cadre de !'evaluation des ressources phytogenetiques spontanees et suite aux travaux de Aguenarous et al. (1988), ii nous a semble interessant d'etudier la variabilite du poids des infrutescences et de mille graines, du nombre de graines par infrutescence et du rapport des poids des graines/infrutescen­ ces, chez T. angustifolium. Les …

Collection Of Native Germplasmn Resources Of Tropical Forage Legumes In Southeast Asia, R Schultze-Kraft, S Pattanavibul, A Gani, C He, C C. Wong

IGC Proceedings (1977-2023)

Southeast Asia is generally considered to be only a minor center of origin of forage legume. Yet, in a comprehensive overview of tropical legumes with forage potential. Williams (1983) listed 68 genera in the Papilionoideae subfa­mily alone whose natural distribution extends to tropical Asia. Moreover, from these come a number of species with well­known commercial varieties, such as Desmodium heterocarpon. D. heterophyllum, D. ovalifolium and Pueraria phaseoloides.

In spite of the potential of native legumes, systematic plant exploration and collection in the region have only been undertaken recently. They are principally the result or collaborative efforts between national agricultural research …

Phalaris Germplasm Screen On A Subtropical Spodosol, W D. Pitman, C G. Chambliss, R A. Lane

IGC Proceedings (1977-2023)

Through the lower U.S. Gulf Coast, lack of forage pro­duction during the typically mild cool season is a major limi­tation to beef cattle production. The combination of cool temperatures, occasional frosts, and low rainfall in peninsular Florida limit growth of warm-season forage species during the cool season. Temperate forage cultivars have failed to provide dependable cool-season forage, with the perennial species even failing to survive the typically hot, humid, occasionally water­logged summer conditions of the Gulf Coast Spodosols. Early forage plant screening in Florida (McCaleb and Hodges, 1958) and more recent research in Alabama (Hoveland et al., 1974) have indicated …

Selection Of Brachiaria Spp. For The Acid-Soil Savannas Of The Central Plateau Region Of Brazil, B Grof, R P. De Andrade, M S. Franca-Dantas, M A. De Souza

IGC Proceedings (1977-2023)

Species of Brachiaria, introduced in the 1950's and 1960's, are wide-spread in both savanna and cleared forest regions of the lowland tropics of South America. Large areas, c. 15 x 106 ha, have been sown to Brachiaria spp. in the Cerrados of Brazil. A major limitation to the use of exotic grasses in the Cerrados is the incidence of spittlebugs. The widely-sown Bra­chiaria decumbens, B. ruziziensis and B. humidicola are all very susceptible to these insect pests. In view of the considerable importance of Brachiaria spp. to the pasture economy of trop­ical America, CIAT's (Centro Internacional de …

Forage Germplasm At The International Livestock Centre For Africa (Ilca): An Essential Resource For Evaluation And Selection, J Hanson, J R. Lazier

IGC Proceedings (1977-2023)

A major constraint to increased livestock production in sub­Saharan Africa is the generally low quality of the feed resources available from natural pastures and crop residues. Although forage research, mainly on other continents, has identified useful genotypes for environmental conditions ranging from temperate to tropical, these have generally not been adopted by African farmers. There is a need for research to select forages acceptable to African farmers and adapted to their diverse environments and farming systems. A diverse genepool of material is essential for the evaluation and selection necessary to identify appropriate forage germplasm which can overcome this constraint. Recognizing …

Distribution And Ecology Of Trifolium Subterraneum Ssp. Yanninicum And Progress With Improvement, W J. Collins, C M. Francis

IGC Proceedings (1977-2023)

Subterranean clover (Trifolium subterraneum L.), Australia's most important pasture legume, is a winter-growing annual which is naturally distributed around the Mediterranean region and parts of western Europe. Three subspecies (or species in some taxonomic treatments) are recognized in subterranean clover and these are represented in the Australian National col­lection as follows : ssp. subterraneum - 4,800 genotypes, ssp. brachycalycinum 1,500 genotypes, ssp. yanninicum - 170 genotypes. The yanninicum subspecies, despite the smallness of the col­lection is of special interest both ecologically and for agriculture. The ability to grow in wet situations, together with good persistence under grazing makes genotypes …

Basic Aspects, Objectives And Preliminary Results Of A Subterranean Clover Improvement Program In Sardinia (Italy), E Piano

IGC Proceedings (1977-2023)

The process of extended agronomical rehabilitation of the heavily deteriorated pastures, activated in Sardinia in the 1970's, has been largely supported by the introduction of subterranean clover (Trifolium subterranuem L. sensu lato) as a cultivated plant in the island. Although this annual self-reseeding species has readily become the most widely sown pasture legume in Sardinia, the broadscale use of imported varieties has not always been an unqualified success, particularly in terms of long-term persist­ence. Therefore, the need to define clearly the particular combi­nation of characters contributing to adaptation in Sardinia, and to develop local varieties specifically "adjusted" to Sardi­nian …

Yield, Flowering Pattern And Leaf Area Diversity In Macroptilium Atropurpureum (Dc.) Urb., A E. Kretschmer Jr, R M. Sonoda, T C. Wilson

IGC Proceedings (1977-2023)

Macroptilium atropurpureum (DC.) Orb. is a twining tropical forage legume. The only commercial cultivar, Siratro, has been tested worldwide in the tropics and subtropics (Krestschmer, 1972; Kretschmer et al., 1985). Since the genetic base for this hybrid was narrow, a good possibility exists to find better agronomic qualities such as persistence, higher yield, greater seed production, and pest resistance within a wider base of germ plasm. To determine the diversity of the species, introduction of germplasm from many of the world's tropical forage germ­plasm banks was begun in the late 1970s and as many of the available entries as possible …

Genotypic Differences In Seedling Vigor In Sericea Lespedeza, J A. Mosjidis

IGC Proceedings (1977-2023)

Slow seed germination and poor seedling establishment have been considered major problems in sericea lespedeza [Lespe­deza cuneata (Dumont de Courset) G. Don.], a summer peren­nial legume grown in the southeastern United States for forage and soil conservation (Logan et al., 1969). Wright et al. (1978) considered sericea lespedeza a nonaggressive species because of the low number of seedlings that emerge and the long time needed for emergence as compared to other species. Hoveland et al. (1971) indicated that sericea lespedeza seedlings are weak and compete poorly with weeds. Recommended planting time of sericea is early spring as soon as there …

Transfer Of Genes For Aphid Resistance From Medicago Truncatula (Barrel Medic) Via M. Littoralis (Strand Medic) To M. Tornata (Disc Medic), W H. Lake

IGC Proceedings (1977-2023)

Since_ the late 1970's, many medic based pasture leys in Australia have been consistently and severely damaged by both blue green aphid (BGA) (Acyrthosiphon kondoi) and to a lesser extent spotted alfafa aphid (SAA) (Theroaphis trifolii fm maculata). Where infested stands are not sprayed, seed set has been severely affected, and this seed set is vital if the system is to ?ea successfull self-regenerating one (Carter, 1981). Aphid resistant cultivars are likely to provide a long term answer to this problem, and since the early 1980's several new resistant barrel medic (M. truncatula) cultivars have been …

The Potential Of Lolium Multiflorum X Festuca Gigantea Hybrids, M O. Humphreys, H Thomas, B F. Tyler

IGC Proceedings (1977-2023)

The potential for combining traits from broadly adapted Festuca with more highly specialised Lolium has been investi­gated for many years especially with regard to cytological behaviour (Breese et al., 1981). In the USA, efforts to increase the nutritive value of tall fescue through hybrids with ryegrasses succeeded in producing the variety Kenhy (Buckner et al., 1977). So far, Lolium/Fescue hybrids have not been able to compete commercially with more productive ryegrasses in intensive UK farming systems (Breese and Lewis, 1984). How­ever, with recent economic changes in European agriculture there is a need for more efficient, lower input grassland …

Evaluation And Hybridization Of Germplasm In The Desmodium Hetercarpon- D. Ovalifolium Species Complex, K H. Quesenberry, M A. Mckellar, D E. Moon

IGC Proceedings (1977-2023)

Although Ohashi (1973) classified Desmodium ovalifolium Wall. as synonimous with D. heterocarpon (L.) DC. and placed both in the same subspecies and variety, most forage resear­chers have chosen to maintain species rank for both taxa. Ohashi's criteria for lumping these two taxa was inflorescences densely flowered with distinctly hooked-hairy pods ; however, germplasm characterization by CIAT (1981) has identified growth habit and flowering pattern as other more complex traits by which these species differ. Desmodium ovalifolium has been shown to have potential for pasture use in the Llanos of Columbia and other acid soil sites (CIAT, 1981). A cultivar of …

Intergeneric Hybridization Between Festuca And Lolium Genus By In Vitro Pollination And By Ovule Transder, Ho-Jin Lee, Ji-Yeon Han

IGC Proceedings (1977-2023)

The barriers to intergeneric crosses in the grass family were commonly known as inviability of the developing embryo, embryo abortion, or endosperm abnormalities, which might have occured after fertilization. To avoid incompatibility in wide cross, in vitro pollination or fertilization techniques have been attempted and made success in Nicotiana (Marubashi and Nakajima, 1985) and in Maize (Gengenbach, 1977). Our program has intended to improve forage quality of tall fescue through crossing to Italian ryegrass. The artificial cross between these genus had relatively low chance for obtaining hybrid offspring. The purpose of this research was to overcome the incompatibility barrier in …

2n Gamete Producer In Diploid Species Of Genus Medicago, F Veronesi, A Mariani, S Tavoletti

IGC Proceedings (1977-2023)

In Medicago genus, the importance of gametes with unreduced chromosome number (2n gametes) has been stressed both in the evolution (Stanford et al., 1972) and breeding (Bingham, 1968) of cultivated alfalfa, wich is a cross-fertilizing natural polysomic polyploid (Medicago sativa L., 2n = 4x = 32). In this species heterozygosity can be maximized but not fixed by the usual methods of cultivar development (Dubier and Bingham, 1975). As an alternative to normal sexual repro­duction, hybridization of 2n gametes from diploid hybrids can transmit, through bilateral sexual polyploidization, a large part of the heterozygosity of the diploid parents to the …