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Pubescence Density Effects on Soybean Seed Yield and Other Agronomic Traits
Author(s) -
Zhang Jianhua,
Specht James E.,
Graef George L.,
Johnson Blaine E.
Publication year - 1992
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/cropsci1992.0011183x003200030013x
Subject(s) - biology , cultivar , transpiration , canopy , horticulture , agronomy , yield (engineering) , trait , breeding program , photosynthesis , botany , computer science , programming language , materials science , metallurgy
An increase in pubescence density can amplify leaf surface reflectivity. Greater leaf reflectivity can reduce transpiration, because it lessens the solar radiation load on the sunlit canopy surface, and can also enhance photosynthesis if more radiation is reflected to the shaded leaves in the lower part of the canopy. Both effects, which improve water.use efficiency, were previously documented when dense ( Pd1Pd1 ) and normal ( pd1pd1 ) pubescence soybean [ Glycine max (L.) Merr.] genotypes were tested as near‐isogenic lines in two specific genetic backgrounds. However, the agronomic value of the Pd1 gene must be verified in a much wider array of genetic material before soybean breeders would consider using the gene in a cultivar development program. Accordingly, four dense and four normal genotypes were randomly extracted as F 3 ‐derived F 5 lines from each of 20 populations that had been created by mating 10 female pd1pld parents with two male Pd1Pd1 parents. The 80 dense and 80 normal lines were evaluated in a 1988 to 1989 performance trial. On average, lines with dense pubescence had greater yield (53 kg ha −l ), maturity (1 d), plant height (4 cm), lodging (0.26 units), and 100‐seed weight (0.7 g), and seed quality (0.06 units). An interaction of pubescence density × test year was evident for yield (dense significantly better in 1988; no better in 1989). The interaction of pubescence density with female parent was significant only for maturity, height, and 100‐seed weight, but the same interaction with male parent was not significant for any trait. Seed yields were somewhat larger for lines with a gray ( tt ), as opposed to tawny ( TT ), pubescence color. As a result, dense‐gray lines were higher yielding than dense‐tawny and normal‐gray lines, which in turn were higher yielding than normal‐tawny lines. Selection of the dense‐gray types in breeding populations segregating for pubescence density and color may be of some merit in terms of soybean yield improvement.