caa a22 4500 477053653 CHVBK 20180405111343.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF02152702 doi (NATIONALLICENCE)springer-10.1007/BF02152702 Intra-fruit seed abortion in a wind dispersed tree, Dalbergia sissoo Roxb: Proximate mechanisms [Elektronische Daten] [B. Mohan Raju, R. Uma Shaanker, K. Ganeshaiah] Dalbergia sissoo, a tropical tree with wind-dispersed pods, exhibits a highly positively skewed distribution of seeds per pod with predominantly only one of the four or five ovules maturing into seed. The abortion cannot be attributed to lack of pollen or resources. This study examines the hypothesis that the abortion is due to an intense rivalry among the developing sibs to gain dispersal advantage. Aqueous extract of the dominant embryos at the stigmatic end that generally develop to maturity significantly inhibited the uptake of labelled sucrose by the young developing (subject) embryos in an in vitro assay system. Extracts of tissues such as subordinate (peduncular embryos), unfertilized ovules and pod coat did not cause such inhibition. Aqueous diffusate of dominant embryos also inhibited the uptake of labelled sucrose by subject embryos. The chemical substance responsible for the inhibition appears to be heat-stable and non-proteinaceous. HPLC analysis indicated the presence of two retention time peaks, different from that of standard indole acetic acid, but with considerable overlap. We hypothesize that the compound could be an indole derivative. We propose that the stigmatic embryos have a head start due to earlier fertilization and produce a chemical that either directly (by metabolically killing) or indirectly (by preventing the uptake of assimilates) kills the proximally placed peduncular embryos. Springer-Verlag, 1996 Dalbergia sissoo nationallicence Seed abortion nationallicence Sibling rivalry nationallicence Diffusate nationallicence 14C sucrose uptake nationallicence Mohan Raju B. Department of Crop Physiology, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut Uma Shaanker R. Department of Crop Physiology, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut Ganeshaiah K. Department of Genetics and Plant Breeding, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut Sexual Plant Reproduction Springer-Verlag 9/5(1996-09-01), 273-278 0934-0882 9:5<273 1996 9 497 https://doi.org/10.1007/BF02152702 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02152702 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mohan Raju B. Department of Crop Physiology, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut NATIONALLICENCE 700 1- Uma Shaanker R. Department of Crop Physiology, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut NATIONALLICENCE 700 1- Ganeshaiah K. Department of Genetics and Plant Breeding, University of Agricultural Sciences, GKVK, 560 065, Bangalore, India aut NATIONALLICENCE 773 0- Sexual Plant Reproduction Springer-Verlag 9/5(1996-09-01), 273-278 0934-0882 9:5<273 1996 9 497 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer