Pollen-Pistil Interaction and Control of Fertilization

Pollen-Pistil Interactions

“…HESLOP-HARRISON and Y. HESLOP-HARRISON 1982). The presence of esterase in some dry stigma types is associated with the ability of the pollen tubes to penetrate the stigma cuticle (SHIVANNA andSASTRI 1981, BERNHARDT et al 1980). Acid phosphatase has also been detected cytochemically in the stigmatic exudate of several species, including (HERRERO and DICKINSON 1979), Linum (GHOSH 1981) and in the cell walls of receptive stigmas of the seagrass Tha/assia (PETTITT 1980).…”

“…In pollen types with higher than 20% water content, e.g., Brassica, DUMAS and GAUDE (1983a, b) show that there is an effective plasma membrane in the living dehydrated grain, which only becomes porous at death. Striking differences between the two types exist: grass pollen quickly loses viability within 1-2 h, and has no lipid seal (SHIVANNA andHESLOP-HARRISON 1981, HESLOP-HARRISON 1979a, b); Brassica pollen retains some viability after dehydration and storage, and has a thick lipid seal (DUMAS and GAUDE 1983).…”

Pollen-pistil interactions inGrevillea banksii

“…typification of Proteaceae as dry rested, though, on only two species. Shivanna (1982) however, admits there is no firm division between wet and dry stigmas. Wet stigmas, often linked with protandry, may be dry at anthesis, as noted for Proteaceae by Bentham (1873) and this is true of G. bariksii.…”

How wide can a wide cross be?

“…In addition to genetic and environmental variability, reciprocal crosses, and independence of pre-and postmating barriers, a detail of other barriers to wide crosses, and various approaches to overcome these, including chromosomal manipulations of the parental species and hybrids, bridge crosses, hormonal application of the florets after pollination, and intra-ovarian fertilization can be found in Hadley & Openshaw (1980), Shivanna (1982), Sharma & Gill (1983a), Sastri & Mallikarjuna (1984), Collins et al . (1984), andPickersgill (1993) .…”