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Breeding Crested Wheatgrass for Seed Size and Yield 1
Author(s) -
Schaaf H. M.,
Rogler G. A.
Publication year - 1963
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/cropsci1963.0011183x000300040020x
Subject(s) - citation , yield (engineering) , crop , biology , library science , agronomy , computer science , physics , thermodynamics
TNCENTIVES for the improvement of seed characters in •*• perennial forage grasses are (1) the low cost of seeding as a means of propagation, (2) age-old problems of stand establishment, and (3) difficulties in seed processing, handling, and planting. Traits most often considered in grassbreeding programs for seed improvement are yield and size. These characteristics are pa r t i cu la r ly important in crested wheatgrass and other range grasses planted on large acreages and usually under adverse conditions. Positive relations between seed size and seedling vigor of forage grasses have been demonstrated by Kneebone (5) and Kneebone and Cremer (6) in sand bluestem, indiangrass, switchgrass, buffalograss, and sideoats grama, by Tossell (11) in smooth brome, and by Lawrence (7) in intermediate wheatgrass. In crested wheatgrass, Rogler (9) found a close relation between seed size and ability to emerge from increasing depths of planting. Seed quality as well as inherited traits other than seed size undoubtedly affect seedling vigor and stand establishment (3). Selection for seed size, however, is a criterion easy to use in breeding for seedling vigor (9). Increased size also improves processing, handling, and planting qualities of grass seed. Detailed knowledge of relations among seed size, yield, and other heritable seed and forage traits is essential for intelligent execution of programs directed at improving these characters. A significant step in that direction was provided by Dewey and Lu (2) with their comprehensive correlation and path-coefficient analysis of components of seed production in a spaced population of crested wheatgrass. The most important components of seed yield were seed set and plant size (mature-plant weight). A significant negative correlation between seed set and plant size, however, intimated the necessity for compromise in selection for the two characters to attain maximum seed yields. On the basis of data from crested wheatgrass strain tests covering an 11-year period, Schaaf et al. (10) reported a very highly significant average correlation, r = +.403, between forage yields and seed sizes obtained in solid plantings and spaced rows, respectively. This report provides information on associations between seed yield and size for selected crested wheatgrass clones and their polycross progenies. In addition, data are pre-