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Growth Rate and Yield in Sericea Lespedeza in Relation to Seed Size and Outcrossing 1
Author(s) -
Cope Will A.
Publication year - 1966
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/cropsci1966.0011183x000600060020x
Subject(s) - outcrossing , biology , heterosis , lespedeza , seedling , germination , agronomy , open pollination , botany , horticulture , pollination , hybrid , pollen
Sericea lespedeza seed were obtained from open‐pollinated chasmogamous flowers and from self‐fertilized cleistogamous flowers from both an outcrossed and a caged plant in each of 10 inbred lines. Chasmogamous seed are approximately 20% heavier than cleistogamous seed; thus, the four progenies in each line allowed comparison of both outcrossing and seed size effects. In a greenhouse test seed size superiority averaged nearly 8% for measurements over a 4‐month period; in the field test initial values were similar but disappeared after 2 months. A superiority for outcrossing was apparent in each test only after several weeks, reaching a maximum of 8.5% over the maternal parents at the end of the first growing season in the field. The small increase from outcrossing possibly reflects both a low level of heterosis and a low percent cross‐pollination. Within the 10 lines seed size was significantly correlated with seedling performance; thus selection for seed size involves genetic factors for growth rate other than seed size alone. Both seed size and heterosis require attention of the plant breeder; however, the levels of effects reported here place definite restrictions on progress to be expected and breeding systems to be used effectively.