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Genetic Variability in Ranger Alfalfa 1
Author(s) -
Kehr W. R.,
Gardner C. O.
Publication year - 1960
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1960.00021962005200010013x
Subject(s) - agricultural experiment station , library science , citation , agricultural science , agriculture , political science , mathematics , horticulture , history , computer science , biology , archaeology
studies as summarized by Atwood and Grtin (1) indicated that diploid inheritance prevailed but that tetraploid inheritance also could have been used as a basis of explanation for observed results in a few instances. More recently the studies of Stanford (8), Twamley (9), Oldemeyer and Dudley and Wilsie (4) showed that tetraploid inheritance was common. A complex situation of tetra-disomic inheritance was suggested by Hanson (5), Twamley (9), and Dudley and Wilsie (4) for some traits. The inheritance of combining ability for forage and seed yield was demonstrated by several workers who concluded that these .characters were quantitative in nature. The literature on combining ability studies was recently reviewed by Kehr and ’Graumann (6). Information on the nature of gene action involved in forage yield is necessary to the development of more efficient breeding methods and the utilization of superior germ plasm in the form of synthetics and hybrids. Each seed available for alfalfa improvement may be viewed as a potential clone. Current emphasis in alfalfa bre~ding is on obtaining clones having a suitable combination of desired traits such as resistance to economically important diseases and insects, abundant yield of high quality forage, and inherent seed-producing ability. The most prevalent basis for selection of clones is the use of the polycross test which provides an estimate of general combining ability. Clones high in get3eral combining ability are utilized in the formulation of synthetic varieties. While selected clones provide an immediate basis for experimental synthetics which may ultimately be commercial varieties, there is a critical need for studies to determine the nature of the gene action controlling quantitatively inherited traits, so that the most efficient breeding system may be devised. Comstock (3) outlined the information of a statistical nature that seemed pertinent to alfalfa breeding as follows: estimates of (!) genotype-environmental interaction variances, (2) genotypic covariances among the economically important characters, and (3) the extent of additivity in gene action. He pointed out that information on items (1) ̄ and (2) could be obtained from data collected from fami-