Registration of Partially Free‐Threshing Diploid Wheat Germplasm

MONOC BULK #1 VV diploid wheat (Triticum monococcum subsp. sinskajae Filat. & Kurk.) (Reg. no. GP-487, P1 584654) germplasm was developed and released by the Cereal Research Institute (Istituto Sperimentale per la Cerealicoltura) in Rome, Italy, in November 1994. The components of this bulked population are partially free-threshing and possess improved agronomic characteristics. MONOC BULK #1 VV should be viewed as a first, tentative step towards the development of commercial cultivars of T. monococcum. Triticum monococcum subsp. monococcum (tenacious-glumed, non-free-threshing) and T. monococcum subsp. sinskajae (softglumed, partially free-threshing) are primitive, cultivated forms of diploid wheat derived from wild T. monococcum subsp. boeoticum (Boiss.) Hayek. Monococcums have been domesticated and cultivated throughout the last few millennia, but have not been subjected to modern breeding procedures. At present, monococcums are grown in only a very few marginal farms of southern Europe and Turkey. Recent studies have shown that the monococcum accessions maintained in germplasm banks possess, as a group, practically all the genes needed to breed diploid wheats possessing the main attributes of modern cultivars of common wheat (T. aestivum L.) and durum wheat(r. turgidum var. durum) cultivars (2). Advantages, perspectives, and problems related with monococcum breeding, cultivation, and utilization have been discussed by various authors (1,2,3). MONOC BULK # 1 VV germplasm is a bulk of equal quantities of seed from 34 F5 lines selected from the cross WIR 48993/V V307. WIR 48993, the soft-glumed parent, is a partially free-threshing diploid wheat accession originally collected in Turkey and first described by Filatenko and Kurkiev (4). It is a late-maturing, wintertype strain, characterized by low vigor and tillering ability, relatively short straw, and reduced spike fertility. It is the only freethreshing monococcum accession thus far identified, and is only partially so. VV307, the tenacious-glumed parent, is a non-freethreshing, medium-early-maturing, tall (135 cm), spring-type diploid wheat strain. MONOC BULK #1 VV was selected for soft glumes, early maturity, and agronomic type, using the classical pedigree method. The resulting population is partially free-threshing and its components head similarly to or 4 to 5 d later than modern cultivars of durum wheat. Plants of the bulked population exhibit a greater vigor and tillering ability, as well as a higher spike fertility, than WIR 48993. Mean kernel weight is about 30 mg, greater than that of either parent and than most monococcum accessions. Grain texture is soft. Mean plant height is about 120 cm, intermediate between that of the two parents and shorter than that of the majority of T. monococcum accessions. Gluten is very weak; SDS sedimentation values for the bulked lines (mean =17 mL; range 13-25 mL) are markedly lower than those of commercial cultivars of durum and common wheat (30-60 mL). Microplot field experiments on highly fertile soils indicate that the maximum grain yield of MONOC BULK #1 VV is about 3500 kg ha". To develop more competitive diploid wheats, selections from the bulked population should be crossed with strains possessing a higher gluten strength (1). Crosses with accessions having a shorter and stronger straw are also necessary, to develop genotypes more responsive to improved growing conditions. Seed of the bulked population is available for breeding and research purposes upon written request to the author. Recipients of seed are asked to make appropriate recognition of the source of the germplasm if it contributes to research or development of cultivars, germplasm, parental lines, or genetic stocks.