Registration of CADL 98 Alfalfa Germplasm.
CADL 98 alfalfa (Reg. no. GP-335, PI 604218) Medicago sativa L. is cultivated alfalfa at the diploid level (2n = 2x = 16). CADL 98 was developed from cultivated tetraploids via haploidy. CADL was described in 1979 (1) and research involving CADL and cultivated 4x alfalfa was reviewed (2). In general, CADL leaves, stems, pollen and seeds are smaller than those of tetraploids (about 50% of 4x) as is herbage yield. Seed reproduced populations circa 1980 represented about equal amounts of germplasm from `Vernal' and `Saranac'. Additional cultivars and experimentals have been scaled-down to the diploid level via haploidy almost every year since 1979. Haploids have been obtained via the 4x-2x cross method since 1979 from the following: `Agate', `Iroquois', `Magnum', `Pioneer 532', `Perry', `WL 225' and Wisconsin experimentals, Wisyn-B, Wisyn-C and Wisyn-X. In addition, spontaneous haploids have been identified among partial inbreds in each of the following: `Columbia 2000', Peruvian (PI 536535) and in W10 germplasm. Over the years about 100 haploids have been used as seed parents and crossed with the previous CADL generation to produce CADL 98. CADL 98 is an interbreeding population in which all plants can be crossed with each other, with new haploids, and with diploids of M. sativa subsp, falcata (L.) and M. sativa subsp, caerulea (Less. ex Lebed.) Schmalh.
CADL 98 is predominantly outcrossing, but most plants also can be self-pollinated, similar to cultivated tetraploid alfalfa. Recessive traits in alfalfa segregate more frequently at the diploid level, and CADL 98 is a rich source of variation. About 10% of CADL 98 plants segregate for one of the following traits among their self progeny: albinos, chlorophyl deficients, seedling lethals, leaf, stem, and growth habit variants, cauliflower head-simple leaf, cream flower color, and restitution pollen and eggs. The low frequency of restitution pollen and eggs produces a low frequency of sexual polyploidy, usually spontaneous tetraploids.
CADL 98 is useful in mapping the genome of cultivated alfalfa, ploidy series research, cytogenetic research, direct crossing with diploids of falcata and caerulea subspp, chromosome doubling to produce tetraploids with only one or two alleles per locus, and all aspects of genetic research where disomic genetic ratios are desirable.
Five grams of seed of CADL 98 will be distributed until the supply is depleted. Seed will be sent upon written request and agreement to recognize the source of the materials when they are used in publication or development of new germplasm or a cultivar. Requests should be sent to the corresponding author.
References and Notes
(1.) Bingham, E.T., and T.J. McCoy. 1979. Cultivated alfalfa at the diploid level: Origin, reproductive stability and yield of seed and forage. Crop Sci. 19:97-100.
(2.) Bingham, E.T., R.W. Groose, D.R. Woodfield, and K.K. Kidwell. Complementary gene interactions in alfalfa are greater in autotetraploids than diploids. Crop Sci. 34:823-829.
(3.) Dep. of Agronomy, 1575 Linden Dr., Univ. of Wisconsin, Madison, WI 53706-1597. Research supported by College of Agric. And Life Sci. Univ. of Wisconsin. Registration by CSSA. Accepted 31 May 1999.
E.T. BINGHAM(*) (3)
(*) Corresponding author (email@example.com).
Published in Crop Sci. 40:298 (2000).
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|Article Type:||Brief Article|
|Date:||Jan 1, 2000|
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