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AMPHIPLOIDY AND INTROGRESSION IN STIPA
Author(s) -
Johnson B. Lennart
Publication year - 1962
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.1537-2197.1962.tb14935.x
Subject(s) - introgression , polyploid , biology , lemma (botany) , stipa , botany , subspecies , ploidy , zoology , poaceae , genetics , gene
J ohnson , B. L ennart . (U. California, Los Angeles.) Amphiploidy and introgression in Stipa. Amer. Jour. Bot. 49(3): 253–262. Illus. 1962.—Frequent specimens heretofore referred to Stipa californica (2 n = 36) were found to be similar to an undescribed polyploid (2 n = 68) species of Stipa on the ratio of lemma to palea length. On other individual diagnostic characters, S. californica and the polyploid were not separable. However, on the discriminant function (Z) comprising 5 such attributes, their mean difference was highly significant. The polyploid is given the new species name, Stipa nevadensis . Appropriate tests using the function Z excluded S. californica as a possible parent of the polyploid and pointed to S. lettermani (2 n = 32) and the combined species S. occidentalis (2 n = 36) and S. elmeri (2 n = 36) as the putative parents. The last 2 species were barely separable on multigenic differences measured by the discriminant function, and the mean Z for S. californica fell near the mid point between them and S. columbiana (2 n = 36). This fact together with evidence from the frequency distribution of Z suggested a hybrid origin for S. californica and introgression with its putative parents.