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Forage Species In Xinjiang Northern Natural Grasslands: Grasses, Li Bao-Jun

Herbarium Publications

Forage germplasm resources, their distributions, potential agronomic characteristics and genetic aspects of the perennial grasses originating in Xinjiang northern regions are discussed. Grass diversity in the natural grasslands is immense for the range of environments to which it is endogenously adapted. Among the perennial species in the mountain area are summer growing and winter-dormant ecotypes, whereas in the plain outland summer-fast-growing, summer-dormant and winter dormant ecotypes occur. Flowering uniformity within the grass tribe provides the chance for gene exchange. The genetic variation for growth rate, tiller development, regrowth and yield between species and within a species has provided plant breeder …

Use Of Annual And Perennial Triticeae Species For Wheat Improvement, A. Mujeeb-Kazi

Herbarium Publications

Constraints due to global biotic and abiotic stress continue to exist in wheat germ plasm. Novel genetic diversity resides in several annual/perennial Triticeae species that can be introgressed into wheat through intergeneric hybridization, of which Thinopyrum curvifolium is the principle source as it addresses the emphasis here for achieving wheat derivatives resistant to Helminthosporium leaf blight (Cochliobolus sativus). Some additional sources like Th. elongatum (2n=2x= 14) and Secale cereale are also mentioned. The interspecific hybridization strategy offers alien genetic introgression opportunities, for which the closely related Triticum species have a priority. Of these sources, the D genome T. tauschii (Aegilops …

Prospects For Gene Lntrogression From Hordeum Bulbosum L. Into Barley (H. Vulgare L.)., R. A. Pickering, A. M. Hill, G. M. Timmerman-Vaughan, E. M. Forbes, M. G. Cromey, M. J. Gilpin, M. Michel, M. Scholz

Herbarium Publications

Hybridizations between Hordeum vulgare L. (cultivated barley) and H. bulbosum L. have been performed over many years with two aims. First, the production of doubled haploid barley cultivars (Kasha and Kao 1970); second, the transfer of desirable traits such as resistance to fungal and viral pathogens from the wild species into barley. Apart from the report of an occasional recombinant (Xu and Kasha 1992; Pickering et al 1994), successful gene introgression has been hampered by several barriers. In this report we will describe recent progress in overcoming these barriers.

Breeding Potential Of Durum Wheat Landraces From Jordan Iv. High Molecular Weight Glutenin Subunit Variation., A. A. Jaradat, M. M. Ajlouni

Herbarium Publications

Variation in high molecular weight glutenin subunit composition among 177 durum wheat genotypes, derived from a collection of durum wheat landraces from Jordan, was investigated using one-dimensional sqdium dodecyl sulphate polyacrylamide gel electrophoresis. A total of 22 alleles, in addition to the null allele, Glu-A I c, were identified; three and seven novel variants were identified at the Glu-A I and Glu-B I loci, respectively. The null allele, Glu-A I c, had the highest (7 6. I%) frequency, followed by Glu-B I b (34. 7% ). Two loci at the Glu-B I locus were lacking, these were Glu-B I c …

Progress In Polyhaploid Production Techniques Of Hexaploid Wheat Through Wide Crosses, M. N. Inagaki, A. Mujeeb-Kazi

Herbarium Publications

(Triticum aestivum L.) through wide crosses were evaluated in terms of pollen sources, 2,4-D application, embryo rescue and chromosome retention. Pollen sources included Hordeum bulbosum L., Zea mays L., Pennisetum glaucum (L.) R. Br., Sorghum bicolor (L.) Moench, and Tripsacum dactyloides (L.) L. Maize-mediated polyhaploid production was more stable than the other methods because of a lesser genotypic influence on embryo formation. Application of 2,4-D onto wheat after pollination was critical to promote seed setting and embryo formation in all cross combinations. Embryo rescue was necessary at an appropriate embryo developmental stage to obtain plant regeneration. Paternal chromosomes were …

Plant Germplasm Resources, S. A. Eberhart, H. E. Bockelman

Herbarium Publications

Landraces and wild relatives of crops from centers of diversity have been rich sources of resistance to new pathogens, insect pests, and other stresses as well as for traits to improve food and fiber quality, animal feed, and industrial products. Because very few crops grown in the U.S. are native, plant introductions are vital to our agriculture. The National Plant Germplasm System (NPGS) was established to acquire, preserve, and distribute plant genetic resources from around the world so that scientists have immediate access to these source materials. The active collection is maintained and distributed by 19 national germplasm repositories. The …

The Evaluation On Crossabilities Of Chinese Wheat Landraces, M. C. Luo, C. Yen, J. L. Yang, Z. L. Yang

Herbarium Publications

The total of 865 accessions of Chinese bread wheat landraces (Triticum aestivum L.) has been investigated on their crossabilities with rye (Secale cereale L.), of which 121 land races showed similar crossability to Chinese Spring, 50 accessions had much higher crossability than Chinese Spring, and 693 varieties were non-crossable with rye or had lower crossability than Chinese Spring. The analysis on the geographical distribution indicated that the landraces with high crossability occurred in most parts of China. Some utilization of high crossability resources was also discussed.

Breeding Potential Of Durum Wheat Landraces From Jordan Ill. Rate And Duration Of Grain Fill, A. A. Jaradat, M. M. Ajlouni

Herbarium Publications

Grain fill of durum wheat coincides with terminal drought and high temperature stress in the Mediterranean region. Genotypic variation for rate and duration of grain fill was studies in 250 landrace durum wheat genotypes collected in Jordan. A quadratic polynomial was used to describe the relationship between kernel weight and accumulated growing-degree-days from anthesis to maturity. Fitted curves were employed to estimate rate and duration of grain fill. Genotypic differences were found for both traits. Genotypes with high grain filling rate and high kernel weight were identified. Based on grain yield per spike, spikelet fertility, 1000-kernel weight, rate and duration …

Proceedings Of The 2nd International Triticeae Symposium, Richard R.-C. Wang, Kevin B. Jensen, Carolyn Jaussi

Herbarium Publications

At the First International Triticeae Symposium, Helsingborg, Sweden, July 29-August 2, 1991, the participants decided that subsequent meetings will be held every three years. Thus, the Second International Triticeae Symposium was held in Logan, Utah, U.S.A, June 20-24, 1994, with USDA Agricultural Research Service's Forage and Range Research Laboratory and Utah State University as hosts.

The purposes of the second symposium were: (I) to exchange the latest scientific information and advancements related to annual and perennial Triticeae species; (2) to promote the exchange of ideas for developing coordinated collaborative research; and (3) to provide an opportunity to see the biodiversity …

Attempts To Produce Alien Addition Lines In Triticum Durum, Domenico Pignone

Herbarium Publications

Aneuploid stocks in durum wheat are few, and alien additions are particularly rare. The present contribution describes the results of a program aimed at the addition of alien chromosomes to tetraploid wheat. Aegilops caudata, Ae. longissima and Dasypyrum villosum were used as chromosome donors. The crossing program involved the production of amphidiploids with the wheat cytoplasm and the recurrent crossing with durum wheat pollen. IS monosomic addition (2n= 29) plants were obtained and partly selfed and/or backcrossed to wheat. Two disomic addition (2n = 30) plants, possessing two different Ae. caudata chromosomes, were obtained; unfortunately they were very weak and …

Evaluation And Utilization Of Biodiversity In Triticeae For Wheat Lmprovement, A. B. Damania, J. Valkoun

Herbarium Publications

To adapt new varieties to a wide spectrum of environments breeders and farmers have emphasized the need for broadening the current narrow genetic base of modern varieties of important cereal crops such as wheat and barley. In response to this need, several thousand samples of indigenously cultivated Triticeae species and their wild relatives have been collected from the centers of diversity. However, gene bank collections are of little use if they are not evaluated and the information disseminated widely. Evaluation is essentially the link between conservation and use. Some of the collected material has been evaluated at the International Center …

Breeding Potential Of Exotic Barley Germplasm, Merja Veteläinen

Herbarium Publications

Utilization of exotic germplasm offers an approach to broaden genetic variability in breeding populations. This study was conducted in order to 1) compare germplasm of exotic origin with adapted Swedish barleys with respect to genetic differences and 2) to evaluate first cycles of pre-breeding i.e. agronomic traits in complex exotic x adapted crosses. Allozyme studies showed the following Nei's gene diversities among parents: 0.13 (adapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster analysis based both on allozyme and agronomic data indicated that parental groups were genetically divergent. Earliness, straw length, number of ears per plant and thousand …

Triticeae: A Tribe For Food, Feed And Fun, Roland Von Bothmer, Björn Salomon

Herbarium Publications

Triticeae is an important tribe in the grass family, Poaceae. It contains the cereals wheat, rye, triticale, and barley as well as a large number of wild species, some of which are utilized as forage grasses. The tribe combines all kind of biological mechanisms and genetic systems: diploids and polyploids; annuals and perennials, inbreeders and outbreeders, and even apomicts. Due to this large variation Triticeae is an excellent model group for research in genetics, plant breeding, genetic diversity, taxonomy, and speciation in plants.

Triticeae is distributed in almost all temperate areas of the world and consists of some 350-450 species …