Investigation of pollen grain germination and retention on the stigma, and pollen tube frequency in the style following compatible (cross) and incompatible (self) pollinations in ‘Nonpareil’ almond [Prunus dulcis (Mill.) D.A. Webb Syn. Prunus amygdalus Batsch.J revealed that rejection of incompatible male gametophytes occurs on the stigma as well as in the style. Self-pollinations are characterized by lower pollen grain retention on the stigma, reduced and delayed pollen germination, and, where pollen germination had occurred, a low frequency of pollen tubes growing through the style. Pollen tube growth slowed greatly after the tubes entered the ovarian locule before they reached the ovule.
The almond ( Prunus amygdalus Batsch) breeding program of the Centro de Investigación y Tecnología Agroalimentaria of Aragón aims to develop new self-compatible and late-blooming cultivars to solve the main problem detected in Spanish almond
-Gastélum and Mircetich, 2005a ; Guzman et al., 2007 ; Harvey and Braithwaite, 1982 ; Wicks and Lee, 1986 ; Wilcox and Ellis, 1989 ; Wilcox and Mircetich, 1985 ). In California alone, ≈400,000 ha of land are devoted to almond and stone fruit culture ( NASS
., 2011 ). Almond is the most important tree nut crop in terms of commercial production, which is limited to areas characterized by a Mediterranean climate ( Kester and Asay, 1975 ). Kernel quality has become an important criterion for modern almond
‘Kochba’ is a high yielding, semi-hard shelled, well-sealed cultivar of almond, with an attractive light colored kernel.
We thank almond growers Roy and Al Amator of Chico, Calif., and Randy Samuelson, ranch foreman, for faithfully implementing the required treatments. Financial support from Dow AgroSciences LLC throughout the project is gratefully
Becherer, Cara Cross, and Peggy Schrader, the cooperation of Chico State University, Chico, Calif., and Paramount Farms, Shafter, Calif., and the helpful advice of Tom Gradziel. This research was supported in part by a grant from the Almond Board of
The almond ( Prunus amygdalus Batsch) breeding program of the Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA) of Aragón aims to develop new self-compatible and late-blooming cultivars to solve the main problem detected in
Although self-compatibility was discovered in almond as early as 1945 ( Almeida, 1945 ), no attention was paid to the issue until the 1970s. The importance of self-compatibility in almond-growing and in breeding for new self-compatible cultivars
among the progeny obtained in the cross between the Spanish almond ‘Garfi’ [ Prunus amygdalus Batsch, syn. P. dulcis (Mill.) D.A. Webb] as the female parent and the North American peach ‘Nemared’ [ P. persica (L.) Batsch] as the pollen donor. ‘Garfi