The self-incompatible RNase S-alleles of Brazilian apple cultivars

Abstract

Apple plants are self-incompatible because a genetic mechanism allows the female reproductive organ to recognize and reject self-pollen or pollen from genetic related individuals and allows non-self pollen to effect fertilization. Thus, there are implications to both breeding strategies and orchard management for fruit production. The purpose of this study was to identify and to characterize the S-RNase alleles of the gametophytic incompatibility among apple cultivars developed in Brazil, seeking to give support for choosing right combinations of parent in the apple breeding programs. It also sought to identify correct combinations of scion/pollinator cultivars of commercial apple orchards. A total of 16 specific S-RNase alleles primers were tested against DNA extracted from 12 Brazilian cultivars and their parents. The molecular analysis confronted to the reference cultivars, showed that the cultivars Daiane, Imperatriz and Princesa have the same incompatibility S3 and S5 alleles, while 'Lisgala' showed the alleles S2 and S5; 'Suprema', S1 and S9; 'Catarina', S1 and S19; 'Joaquina' and 'Fred Hough', S5 and S19; 'Baronesa', S3 and S9; 'Duquesa', S2 and S3. For 'Primícia' and 'Condessa' it was only possible to identify one of the S-alleles, namely S24 and S2, respectively, with the second allele remaining to be identified. Progeny test indicated the Mendelian inheritance for RNase alleles. Results of this study will be helpful to judiciously choose parents in apple breeding programs to improve compatibility.

Apple Pollination Biology for Stable and Novel Fruit Production: Search System for Apple Cultivar Combination Showing Incompatibility, Semicompatibility, and Full-Compatibility Based on theS-RNaseAllele Database

“…"Beniroman" fruit ripens in the middle of August, which makes it one of the earliest cultivars in Japan. We made the cultivar in "Togokusan Fruit Park" located close to Nagoya in Aichi in central Japan, and surprisingly, it ripened at the end of July with high red pigmentation despite extremely high temperatures (33)(34)(35) ∘ C during daytime) ( Figure 5). The S-RNase genotype of "Beniroman" was identified as S 3 S 5 .…”

Determination of S-genotype in apple and sweet cherry cultivars released at Fruit Research Institute, Cacak

“…Despite the huge genetic variability of apple germplasm in the world, the genetic base of cultivated apples has greatly eroded over time, because the breeders have used a very limited gene pool. In earlier programmes, 'Cox's Orange Pippin' (S5S9), 'Golden Delicious' (S2S3), 'Jonathan' (S7S9) and 'McIntosh' (S10S25) dominated as parental cultivars (NOITON and ALSPACH, 1996), whilst 'Gala' (S2S5) and 'Fuji' (S1S9) are now the most commonly used cultivars (DE ALBUQUERQUE JR. et al, 2011). Consequently, this strategy has led to breeding of mutually incompatible cultivars, because of the few S-alleles which occur at a high frequency.…”

“…Since the modern cultivars are developed from the breeding programmes using limited number of parental cultivars, i.e. 'Golden Delicious' (S2S3), 'Jonathan' (S7S9), 'Fuji' (S1S9), these explain over-representation of some alleles such as S2, S3, S5 and S9 (BROOTHAERTS, 2004;DREESEN et al, 2010;DE ALBUQUERQUE JR. et al, 2011). In contrast, the parentage of old cultivars is mainly unknown, therefore autochthonous apple germplasm is rich and diverse in properties.…”

Identificação por PCR dos alelos-S associados à compatibilidade gametofítica em ameixeira japonesa

“…Ela também pode auxiliar no desenho de pomares, o que garante uma eficiente polinização com uso de cultivares totalmente compatíveis (Albuquerque et al, 2011).…”