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A CYTOLOGICAL STUDY OF BLACK GRAMAGRASS BOUTELOUA ERIOPODA
Author(s) -
Streetman L. J.,
Wright Neal
Publication year - 1960
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1960.tb07166.x
Subject(s) - biology , gametophyte , endosperm , botany , ploidy , anthesis , chromosome , meiosis , pollen , embryo , apomixis , microspore , megaspore , genetics , ovule , stamen , gene , cultivar
S treetman , L. J., and N eal W right . (U.S.D.A., U. Arizona, Tucson.) A cytological study of black gramagrass, Bouteloua eriopoda. Amer, Jour. Bot. 47 (9) : 786–793. Illus. 1960. The chromosome number, microsporogenesis, embryo‐sac development and embryogeny of Bouteloua eriopoda (Torr.) Torr. were investigated. Thirty‐four of the 35 accessions had a diploid chromosome complement of 2 n =20. One accession had a chromosome number of 2 n =28. Meiotic behavior of the 20‐chromosome plants was normal, and pollen quality approached 100%. However, metaphase‐I and anaphase‐I cells of the 28‐chromosome plants had up to 8 lagging chromosomes. Pollen quality was approximately 67%; however, the plants were highly sterile. These results furnished evidence of a basic number of x = 10 for the genus Bouteloua . Megagametophyte development was normal, which resulted in an 8‐nucleate embryo sac of the “ Polygonum” type. Abnormal development of nucellar tissue was not detected, and embryo development did not begin until 12–18 hr. after anthesis. The development of the female gametophyte indicated sexual reproduction. A high degree of morphological variability among and within accessions afforded further evidence for sexual reproduction and suggested that the species was largely cross‐fertilized. The proembryo, which began development 12–18 hr. after pollination, lacked a discernible arrangement of cells and sequence of division. The endosperm was free nuclear until 4 days after pollination, when it changed to a cellular form. Differentiation of the proembryo into various embryo structures began 4–5 days after pollination. The embryo matured anatomically 12 days after pollination. Black gramagrass, a perennial range grass native to the desert grasslands of the southwestern United States, is a major species in Arizona, New Mexico, and adjacent parts of Mexico. In many areas of low rainfall this species is the only desirable grass.