Ru. Shaanker et al., DOES ENDOSPERM REDUCE INTRA-FRUIT COMPETITION AMONG DEVELOPING SEEDS, Plant systematics and evolution, 201(1-4), 1996, pp. 263-270
The evolution of endosperm, the tissue that nourishes developing embry
os, has remained an enigma owing to its unique genetic composition. Be
cause it contains both maternal (generally 2 doses) and paternal (1 do
se) genomes, it is suggested to have evolved as a compromising tissue
between the evolutionary interests of the maternal parent and offsprin
g over resource allocation. This argument implies that in species wher
e endosperm is highly functional and persistent, it quenches competiti
on among developing embryos for resources and facilitates an equitable
resource allocation to the developing offspring. Based on this argume
nt we predict the association of well developed endosperm with certain
features of fruits such as high ovule number per ovary and low extent
of seed abortion. In this paper, we provide evidence in support of th
ese predictions by analysing the data from 1131 species from the Flora
of Presidency of Madras. We show that persistent and functional endos
perm is more frequent in multiovulated than in uniovulated species and
in species with less seed abortion. Our results also suggest that spe
cies with well developed endosperm tend to have uni-carpelled ovaries.
Our analyses show that these associations are less likely to be emerg
ing due to phylogenetic constraints. We argue that the endosperm has e
volved as a maternal strategy of quenching the extent of sibling rival
ry.