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Cytology and Crossing Behavior of Triploid Alfalfa 1
Author(s) -
Binek A.,
Bingham E. T.
Publication year - 1970
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1970.0011183x001000030028x
Subject(s) - biology , pollen , germplasm , ploidy , medicago sativa , chromosome , cytology , botany , cytogenetics , chromosome pairing , inflorescence , aneuploidy , genetics , gene
Cytology and crossing behavior of triploid alfalfa (2n=3x=24) were studied in 15 plants from 2x‐4x and 4x‐2x crosses involving Medicago sativa and M. falcata . Chromosome associations in PMCs averaged 2 to 3 trivalents, 5 to 6 bivalents, and 3 to 4 univalcnts. Triploids were effectively male sterile although pollen grains were about 32% germinable in sucrose solution. Seed set was higher in 3x‐4x crosses than in 3x‐2x crosses. 3x‐2x progeny ranged from 16 to 32 chromosomes. Among 61 progeny examined there were 40 with 16 chromosomes, seven trisomics, nine double trisomics, three plants with 30 chromosomes, and two plants with 32. 3x‐4x progeny ranged from 28 to 40 chromosomes. Among 229 progeny, there were 78 (34%) with 32 chromosomes, 109 (4870) aneuploids with fewer than 32 chromosomes, and 35 (15%) aneuploids with greater than 32. About 3% of the functional female gametes were unreduced and gave rise to tetraploids from 3x‐2x crosses and pentaploids from 3x‐4x crosses. Use of triploids in cytogenetic research and in germplasm transfer was discussed.