Abstract
BACKGROUND:
Hybrid breakdown has been well
documented in various species. Relationships between genomic heterozygosity and traits-fitness have been
extensively explored especially in the natural populations. But correlations
between genomic heterozygosity and vegetative and reproductive traits
in cotton interspecific populations have not
been studied. In the current study, two reciprocal F2 populations were
developed usingGossypium hirsutum cv. Emian 22 and G.
barbadense acc. 3-79 as parents to study hybrid breakdown in cotton. A
total of 125 simple sequence repeat (SSR) markers were used to genotype the two
F2 interspecific populations.
RESULTS:
To guarantee
mutual independence among the genotyped markers, the 125 SSR markers were
checked by the linkage disequilibrium analysis. To our knowledge, this is a
novel approach to evaluate the individual genomic heterozygosity. After marker checking, 83 common loci
were used to assess the extent of genomic heterozygosity. Hybrid breakdown was
found extensively in the two interspecific F2 populations particularly on the
reproductive traits because of the infertility and the bare seeds. And then,
the relationships between the genomic heterozygosity and
the vegetative reproductive traits were investigated. The only relationships
between hybrid breakdown and heterozygosity were
observed in the (Emian22 × 3-79) F2 population for seed index (SI) and boll
number per plant (BN). The maternal cytoplasmic environment may have a
significant effect ongenomic heterozygosity and on correlations between heterozygosity and reproductive traits.
CONCLUSIONS:
A novel approach
was used to evaluate genomic heterozygosity in cotton;
and hybrid breakdown was observed in reproductive traits in cotton.
These findings may offer new insight into hybrid breakdown in
allotetraploid cotton interspecific
hybrids, and may be useful for the development of interspecific hybrids for cotton genetic improvement.
http://www.ncbi.nlm.nih.gov/pubmed/27072350
doi: 10.1186/s12863-016-0366-5.(IF=2.14)
PMID:27072350