Detection of genetic factors controlling pollen–style interaction in maize

Abstract

In order to detect loci specifically related to pollen-style interaction in maize, linkage analysis to RFLP markers was performed on a population of recombinant inbred lines, the pollen of which was used to pollinate female plants of two different genotypes: the F1 from which the recombinant inbred population was derived ('self female') and a genetically unrelated hybrid genotype ('cross female'). Besides pollen grain germinability and pollen tube growth rate on the two females, pollen general competitive ability and pollen specific competitive ability for both traits were evaluated, following the procedure used to estimate general and specific combining ability, applied to the pollen-style genetic combination instead of to the hybrid genetic combination. A clear advantage of recombinant inbred line pollen, in terms of germination and early growth, was revealed on self female tissues whereas an inverse effect was detected for tube growth rate: tube growth, until fertilization, was faster on the female of unrelated genotype. Linkage analysis to molecular markers (RFLP) of germinability and of tube growth rate on the two stylar genotypes identified nine QTLs for the first trait on the self and eight on the cross female; four chromosome regions for tube growth rate were detected on the self and 11 on the cross style. Most of the general competitive ability effects were localized in the regions where QTLs for germinability or pollen tube growth were detected, in particular on the cross female; on the contrary, most of the loci for pollen specific competitive ability effects proved to be localized in different chromosome regions.

Inbreeding and outbreeding effects on pollen fitness and zygote survival in Silene nutans (Caryophyllaceae)

“…(1996 ) showed that self pollen penetrate the stigma surface in significantly lower proportions than outcross pollen (23–37% and 80–84%, respectively). This germination difference is much larger than the fitness differences we estimated between self and outcross pollen, suggesting either that stigma penetration is more even in our material, or that the difference disappears later in the life of pollen tubes ( Sari‐Gorla et al ., 1995a , b).…”

Selection on pollen donors by Echium vulgare (Boraginaceae)

“…The small differences could not be explained by the number of pollen tubes in the style, or by early pollen tube growth rate. A negative correlation between early pollen tube growth and late pollen tube growth has been shown for maize (Sari-Gorla et al 1995). If a similar negative correlation holds true for E. vulgare, competition between pollen tubes at a later stage could explain the ifferences between the two experiments in siring success of the cross-pollen donors.…”

Pollen Performance of Plants in Recently Burned and Unburned Environments

“…Pollen germination, pollen-tube growth, and fertilization ability have been shown to differ significantly among recipients from different subspecies (Carney et al, 1994), different inter-mate distances (Waser et al 1987, Cruzan 1990, Waser and Price 1991, and different recipient genotypes (Pfahler 1967, Pittman and Levin 1986, Fenster and Sork 1988, Aizen et al 1990, Marshall and Folsom 1991, Snow and Spira 1992, Cruzan 1993. These effects of recipients on pollen performance or fertilization ability have been attributed to differences in both the growth environment of recipient plants (Fenster andSork 1988, Marshall andFolsom 1991) and genetic make-up of recipients (Pfahler 1967, Pittman and Levin 1986, Cruzan 1990, Sari-Gorla et al 1995). In the current study, front distances differed between sibships of recipient plants in C. unguiculata, suggesting that recipient influences on pollen performance were inherited from their maternal parent.…”