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Variation for Nitrogen Fixation Among Progenies of a Virginia ✕ Spanish Peanut Cross 1
Author(s) -
Arrenddell S.,
Wynne J. C.,
Elkan G. H.,
Isleib T. G.
Publication year - 1985
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/cropsci1985.0011183x002500050033x
Subject(s) - nitrogenase , biology , cultivar , nitrogen fixation , heritability , arachis hypogaea , germplasm , horticulture , population , dry weight , botany , agronomy , genetics , demography , sociology , bacteria
One method of increasing symbiotic N 2 fixation is to improve the N 2 ‐fixing potential of the host plant. Peanut ( Arachis hypogaea L.) cultivars of the Virginia (ssp. hypogaea var. hypogaea ) and Spanish (ssp. fastigiata Waldron var. vulgaris Harz.) types differ in their ability to fix N 2 . This study's objective was to determine the variation and relationship of traits indicative of N 2 fixed for late generation progenies from the cross of a Virginia and Spanish cultivar. The variability for traits indicative of N 2 fixation activity was investigated for 30 F 2 families in the F 5 and F 6 generation from the cross of the Virginia cv., NC 6, and the Spanish breeding line, 922. Nodule number, nodule weight, nitrogenase activity measured by acetylene reduction, specific nitrogenase activity, and shoot weight were measured at three sampling dates at two locations for 2 yrs for the parental lines and F 2 families. Fruit weight was determined on the final sampling date for all entries. Cultivar NC 6 was superior to 922 for all measured traits except specific nitrogenase activity. Significant variation was observed among families for most traits. Broad sense heritability estimates for nodule number, nodule weight, nitrogenase activity, shoot weight and fruit weight were moderate to high, indicating that superior genotypes within this population could be readily identified. Nodule number and weight were positively correlated with each other and with nitrogenase activity, suggesting that only nitrogenase activity was required to identify superior families. Phenotypic and genotypic correlations of nitrogenase activity with shoot weight were significant with genotypic correlations ranging from 0.66 to 0.89 over sampling dates and environments. However, correlations of nitrogenase activity and yield were lower (0.36 for F 5 , 0.57 for F 6 and 0.47 over generations) suggesting that nitrogenase activity has less effect on fruit weight than on shoot weight. Selection for families with greater N 2 ‐fixing activity should be possible and should result in indirect selection for yield.