The recent treatment of
Triticum
by Mac Key (
2005
) (broad species concept) is compared to the classical treatment by Dorofeev et al. (
1979
, English translation expected) (narrow species concept). ...A detailed infraspecific treatment was abandoned by Mac Key. Following his revision, names for many of the infraspecific taxa become obsolete. This is regarded to be a disadvantage for biodiversity and genetic resources studies. We propose maintaining ×
Triticosecale
Wittm. as a nothogenus, with ×
T. rimpaui
Wittm. for octoploid races, ×
T. neoblaringhemii
A. Camus for hexaploid races and ×
T. semisecale
(Mac Key) K. Hammer et A. Filat. (new combination) for tetraploid races.
The recent treatment of Triticum by Mac Key (2005) (broad species concept) is compared to the classical treatment by Dorofeev et al. (1979, English translation expected) (narrow species concept). A ...detailed infraspecific treatment was abandoned by Mac Key. Following his revision, names for many of the infraspecific taxa become obsolete. This is regarded to be a disadvantage for biodiversity and genetic resources studies. We propose maintaining XTriticosecale Wittm. as a nothogenus, with XT. rimpaui Wittm. for octoploid races, XT. neoblaringhemii A. Camus for hexaploid races and XT. semisecale (Mac Key) K. Hammer et A. Filat. (new combination) for tetraploid races.
In this paper, the wheat landraces of Oman are chacterized. Their main constituents are Triticum aestivum L. ssp. aestivum, T. aestivum ssp. hadropyrum (Flaksb.) Tzvel., T. compactum Host, T. ...aethiopicum Jakubz.ssp. aethiopicum, T. aethiopicum ssp. vavilovianum Jakubz. et A. Filat. and T. dicoccon Schrank. The classification of the landraces was performed using a morphological method developed by Dorofeev, Filatenko et al. (1979), considering species, subspecies, convarieties and a great number of botanical varieties. Single landraces contained up to three different species ("Sareeaa") and up to 17 different botanical varieties ("Missani"). T. aethiopicum var. hajirense A. Filat. et K. Hammer is newly described. Keys for the determination of important Omani wheat races are proposed. A detailed list describing origin, local names, and infraspecific taxa of the material is provided. Transformation processes of the oasis settlements lead to a replacement of the traditional agricultural systems and the landraces are threatened by genetic erosion.
Key message
We present a comprehensive survey of cytogenetic and genomic diversity of the GGA
t
A
t
genepool of wheat, thereby unlocking these plant genetic resources for wheat improvement.
Wheat ...yields are stagnating around the world and new sources of genes for resistance or tolerances to abiotic traits are required. In this context, the tetraploid wheat wild relatives are among the key candidates for wheat improvement. Despite its potential huge value for wheat breeding, the tetraploid GGA
t
A
t
genepool is largely neglected. Understanding the population structure, native distribution range, intraspecific variation of the entire tetraploid GGA
t
A
t
genepool and its domestication history would further its use for wheat improvement. The paper provides the first comprehensive survey of genomic and cytogenetic diversity sampling the full breadth and depth of the tetraploid GGA
t
A
t
genepool. According to the results obtained, the extant GGA
t
A
t
genepool consists of three distinct lineages. We provide detailed insights into the cytogenetic composition of GGA
t
A
t
wheats, revealed group- and population-specific markers and show that chromosomal rearrangements play an important role in intraspecific diversity of
T. araraticum
. The origin and domestication history of the GGA
t
A
t
lineages is discussed in the context of state-of-the-art archaeobotanical finds. We shed new light on the complex evolutionary history of the GGA
t
A
t
wheat genepool and provide the basis for an increased use of the GGA
t
A
t
wheat genepool for wheat improvement. The findings have implications for our understanding of the origins of agriculture in southwest Asia.
Key message We present a comprehensive survey of cytogenetic and genomic diversity of the GGA.sup.tA.sup.t genepool of wheat, thereby unlocking these plant genetic resources for wheat improvement. ...Wheat yields are stagnating around the world and new sources of genes for resistance or tolerances to abiotic traits are required. In this context, the tetraploid wheat wild relatives are among the key candidates for wheat improvement. Despite its potential huge value for wheat breeding, the tetraploid GGA.sup.tA.sup.t genepool is largely neglected. Understanding the population structure, native distribution range, intraspecific variation of the entire tetraploid GGA.sup.tA.sup.t genepool and its domestication history would further its use for wheat improvement. The paper provides the first comprehensive survey of genomic and cytogenetic diversity sampling the full breadth and depth of the tetraploid GGA.sup.tA.sup.t genepool. According to the results obtained, the extant GGA.sup.tA.sup.t genepool consists of three distinct lineages. We provide detailed insights into the cytogenetic composition of GGA.sup.tA.sup.t wheats, revealed group- and population-specific markers and show that chromosomal rearrangements play an important role in intraspecific diversity of T. araraticum. The origin and domestication history of the GGA.sup.tA.sup.t lineages is discussed in the context of state-of-the-art archaeobotanical finds. We shed new light on the complex evolutionary history of the GGA.sup.tA.sup.t wheat genepool and provide the basis for an increased use of the GGA.sup.tA.sup.t wheat genepool for wheat improvement. The findings have implications for our understanding of the origins of agriculture in southwest Asia.
Morphological spike diversity of Omani wheat Al Khanjari, S; Filatenko, A. A; Hammer, K ...
Genetic resources and crop evolution,
12/2008, Letnik:
55, Številka:
8
Journal Article
Recenzirano
Little is known about the diversity of field crops in Oman. The objective of this study therefore was to characterize wheat accessions from this country using individual spikes collected from ...different wheat cultivation areas. The phenotypic assessment of 15 qualitative and 17 quantitative characters showed variations among Omani wheat landraces. The standardized phenotypic diversity index (H') was with 0.66 higher for quantitative characters than for qualitative characters (0.52) in tetraploid wheats and with 0.63 and 0.62, respectively, in hexaploid wheats. Overall, the morphological data revealed a surprisingly high diversity among landraces and showed that simple morphological characters can be used for an effective characterization of diversity in Omani wheat.
After 23 years of war, current information about the biodiversity of crops in the Hindukush mountains of Afghanistan is scarce. This study aimed at assessing the genetic composition of farmers wheat ...(Triticum spp.) populations through a survey of 21 randomly chosen cereal fields on both sides of the Panjsher river in the upper Panjsher valley of Northern Afghanistan. A stratified sampling of wheat heads according to morphological differences was followed by estimates of field size and grain yield and a formal interview with the landowner about the cropping sequence and the inputs used. About 75% of the cereal fields were cropped in rotation systems with faba bean (Vicia faba L.), barley (Hordeum vulgare L.), potato (Solanum tuberosum L.), maize (Zea mays L.) or fallow. Manure application at between 2.3 and 5.3 t ha-1 was the major source of nutrient inputs at grain yield levels between 1.2 and 4.7 t ha-1. The morphological characterization of the collection revealed 19 taxonomically different varieties of bread wheat (Triticum aestivum L.) but also barley and triticale (Triticosecale Wittm.) grown in mixtures. Populations within one field consisted of up to seven botanical wheat varieties. Farmers did not differentiate between morphological differences within such mixtures but identified their populations instead according to grain color, cooking properties and resistance to mildew and frost. Triticum aestivum var. subferrugineum was the most widespread wheat variety and no effects of altitude on biodiversity of wheat was noted across the transect. Particularly interesting was the occurrence of T. aestivum var. subferrugininflatum and var. subgraecinflatum which so far have only been reported from Mongolia. The finding of triticale indicated the active seed exchange with lowland or long-distance seed sources.
We present a comprehensive survey of cytogenetic and genomic diversity of the GGA
A
genepool of wheat, thereby unlocking these plant genetic resources for wheat improvement. Wheat yields are ...stagnating around the world and new sources of genes for resistance or tolerances to abiotic traits are required. In this context, the tetraploid wheat wild relatives are among the key candidates for wheat improvement. Despite its potential huge value for wheat breeding, the tetraploid GGA
A
genepool is largely neglected. Understanding the population structure, native distribution range, intraspecific variation of the entire tetraploid GGA
A
genepool and its domestication history would further its use for wheat improvement. The paper provides the first comprehensive survey of genomic and cytogenetic diversity sampling the full breadth and depth of the tetraploid GGA
A
genepool. According to the results obtained, the extant GGA
A
genepool consists of three distinct lineages. We provide detailed insights into the cytogenetic composition of GGA
A
wheats, revealed group- and population-specific markers and show that chromosomal rearrangements play an important role in intraspecific diversity of T. araraticum. The origin and domestication history of the GGA
A
lineages is discussed in the context of state-of-the-art archaeobotanical finds. We shed new light on the complex evolutionary history of the GGA
A
wheat genepool and provide the basis for an increased use of the GGA
A
wheat genepool for wheat improvement. The findings have implications for our understanding of the origins of agriculture in southwest Asia.
Due to its geographic position on the northeastern tip of the Arabian Peninsula and its sea trade relationships with Asia, East Africa and the Middle East, Oman has for millennia been at the ...cross-roads of inter-regional exchange of cultivated plants. This is reflected in recent findings of new cultivars of banana (Musa spp.) and wheat (Triticum spp.) in remote oases of the Hajar Mountains in northern Oman. Material collected in 2003 and 2004 contained six new botanical varieties of wheat which are described here. One of them belongs to the tetraploid T. aethiopicum, the others are hexaploid.
PDF
