ALLPHIN, LOREEN*, TATE TISCHNER, KEVIN CHASE †, JIM ORF ‡, FRED ADLER †, AND KARL G. LARK †. * Department of Botany and Range Science, Brigham Young University, Provo, UT 84602, †Department of Biology, University of Utah, Salt Lake City, UT 84112, ‡Department of Agronomy and Plant Science, University of Minnesota, St. Paul, MN 55108. - Genetics of seed abortion and reproductive traits in soybean, Glycine max (L.) Merr., I.
Genetic basis of embryo abortion in Glycine max was analzyed
using a large Recombinant Inbred (RI) population. RI lines (including
three replicates), parental lines (Minsoy & Noir 1) and
"Check" cultivars were planted in hill plots. Fifty fruits
from each hill were analyzed for reproductive, quantitative traits
(number of ovules per pod, number of filled seeds per pod, seed/ovule,
and developmental stage and position of abortions). Parental lines
differed significantly for traits. Average values for the RI
population were intermediate between the parents. Some segregants had
high frequencies of four ovules or seeds per pod, whereas parents and
"Checks" did not. There was a positive correlation between
yield and ovules per pod and between seed number and ovules per pod.
No correlation was observed between variation in pod size and
seed/ovule. If abortion occurred within a pod there was a greater
probability that another abortion would occur at the same
developmental stage. Most abortions fell in the first position within
the fruit. Abortions were observed at all developmental stages, but
primarily occurred at two of four stages. Six significant QTLs were
associated with reproductive traits. QTLs accounted for 36% of the
variation in ovule or seed number. Two QTLs were involved in
interactions with another locus.
Key words: Glycine max, QTL, reproduction, seed abortion, seed/ovule, soybean