Elucidating the behaviour of pollen tubes in intra-and interspecific pollinations of Phaseolus vulgaris L. and P. coccineus Lam.

Abstract

The behaviour of pollen tubes in intra-and interspecific pollinations of P . vulgaris and P. coccineus has been examined using a combination of phase-contrast, and UV fluorescence microscopy. The results indicate that P . coccineus is self-compatible in terms of pollen tube growth, and that pollen tube inhibition is not responsible for the reciprocal differences in seed set which have been observed in crosses between these species .

Pollen grain germination and pollen tube growth following in vivo and in vitro self and interspecific pollinations in annual Cicer species

“…However, farther down the style, both diameter and fluorescence of the pollen tubes decreased and growth was associated with deposition of callose at irregular distances as well as the formation of callose plugs. Similar findings were reported by HAWKINS & EVANS (1973). These results confirm the observations of MARTIN (1959) that the quantity and distribution of callose are quite variable.…”

“…However, as they travelled down the style, the pollen tubes became slender and intensity of the fluorescence decreased. Similar observations were reported by HAWKINS & EVANS (1973) in PhaseoZus. In a few cases, pollen grains germinated on the style or ovary wall, but were unable to penetrate it; rather they formed short pollen tubes alongside the style or ovary wall, or the pollen tube twisted and folded back. This is in contrast to the findings of REGER & JAMES (1982) who reported pollen germination on the stigma as well as on the style and ovary in sorghum [Sorghum bicolor (L.) MOENCH], pearl millet and maize.…”

“…Pollen tube growth was similar in self and cross pollinations and no inhibition of growth of foreign pollen tubes occurred, as has been also reported by HAWKINS & EVANS (1973). However, the findings of this study are in sharp contrast to those of MERCY & KAKAR (1975) who reported a strong pre-fertilization barrier in the form of failure of pollen germination and penetration of pollen tubes in the stylar tissues of the cross C. arietinum x C. soongaricum J. and S.…”

Pollen germination and pollen tube growth following self-pollination and intra- and interspecific pollination of Medicago species

“…Many pollen tubes grew rapidly down the style and were characterized by small widely spaced callose plugs similar to those observed in apples by STOTT (1972). The majority of the pollen tubes were closely associated with the vascular tissue which may have considerable nutritional and chemotropic influence on their growth as suggested for Phaseolus (Hawkins & Evans, 1973). The first pollen tubes entered the ovule about 12 h and all ovaries had at least one fertilized ovule 30 h after pollination.…”

“…MARTIN (1959) used the fluorescent reaction of callose plugs in pollen tubes to determine growth of the tubes in stylar tissue and thus differentiate between compatible and incompatible crosses in several flowering plants. The behaviour of pollen tubes in intra-and interspecific pollination of Phaseolus vulgaris and P. coccineus was examined using a combination of phase contrast and UV fluorescence microscopy (HAWKINS & EVANS, 1973).…”