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Cytogenetics of Paspalum urvillei ✕ P. juergensii and P. urvillei × P. vaginatum Hybrids 1
Author(s) -
Burson Byron L.,
Bennett Hugh W.
Publication year - 1972
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/cropsci1972.0011183x001200010037x
Subject(s) - biology , bivalent (engine) , hybrid , meiosis , chromosome pairing , ovule , megaspore , cytogenetics , botany , ploidy , chromosome , genetics , embryo , gene , metal , chemistry , organic chemistry
Paspalum urvillei , 2n = 4x = 40, was crossed with P. vaginatum , 2n = 2x = 20, and P. juergensii , 2n = 2x = 20. A morphologically different type of P. urvillei (480) was also crossed with P. vaginatum . Three P. urvillei ✕ P. vaginatum , five P. urvillei 480 ✕ P. vaginatum and 28 P. urvillei ✕ P. juergensii hybrids were produced. This represents a crossability of 0.7%, 1.3%, and 1.1%, respectively, which is high for this genus. All hybrids were 2n = 3x = 30. Meiosis in P. urvillei ✕ P. vaginatum and P. urvillei 480 ✕ P. vaginatum hybrids was very irregular with numerous laggards and micronuclei. Their mean pairing relationships were 1.89 II, 26.23 I and 1.25 II, 27.50 I respectively. P. urvillei ✕ P. juergensii hybrids had bivalent and univalent chromosome associations at meiosis with some laggards and micronuclei. The mean pairing relationships were 9.89 II and 10.29 I per cell. Chromosome pairing suggests a common genome in P. urvillei and P. juergensii but very little homology between P. urvillei and P. vaginatum . Megasporogenesis was normal in all hybrids. However, the functional megaspore generally deteriorated and an ovule without an embryo sac resulted. Sexual sacs in various stages of development were present in 1% of the ovules observed. None of the hybrids produced seed.