Cytoplasmic male sterility, resistance to gall mite and mildew, and season of leafing out in black currants

Abstract

Cytoplasmic male sterility (ems) is described in the Ft hybrids Ribes x carrierei (R. glutinosum albidum x R. nigrum) and R. sanguineum x R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F: I + S suggested that two linked genes controlled ems, F plants being dominant for one (Rfl) and recessive for the other (Rf2).Segregation for ems in relation to three linked genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sphj (resistance to American gooseberry mildew, Sphaerotheca mars-uvae) and Lfi (one of two dominant additive genes controlling early season leafing out) indicated that Rfi and Rf2 were in this linkage group. The gene order and approximate crossover values appeared to be: Ce* WI 0.24 Rf2 Lfl Sph3. Crossover values of 0.36 for Ce-Lfi, and 0.15 for Lfi-Sph3 were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph3.It is suggested that competitive disadvantage of Ifi-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph3. Poor performance of lft-(and possibly 1&-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).

Genetic background of resistance to gall mite in Ribes species

“…Resistance of R. sanguineum to gall mite and mildew has been reported by Keep (1986). This species was used as a donor of resistance in heredity research (Keep 1981, Goodman et al 1987, Siksnianas et al 2008.…”

“…Interspecific R. nigrum x R. uva-crispa hybrids inherit Ce gene at a 1:1 ratio in F 1 . The main problem is that hybrids are mostly infertile and the majority of the R. uva-crispa, R. sanguineum or R. aureum genome is lost during the earliest stages of backcrossing (Keep 1986, Siksnianas et al 2008. F 1 hybrids of interspecific crosses of gooseberry and blackcurrant are weakly developed and have low agronomic value.…”

“…In temperate climate zone, late flowering reduces the risk of currant flower damage during spring frosts. It was shown that early flowering and adaptivity in Ribes species are determined by cytoplasm, and therefore interspecific R. nigrum x R. americanum F 1 hybrids and their progeny were open pollinated in the field conditions with pollen from R. nigrum cultivars with low frequency of P gene (Keep 1986, Siksnianas et al 2005.…”

Cecidophyopsis mites and blackcurrant reversion virus on Ribes hosts: Current scientific progress and knowledge gaps

“…Sequencing of Ce gene associated amplification fragments in different species revealed homology with the amplicons from R. uva‐crispa , indicating the possible Ce gene associated resistance also in R. sanguineum and R. aureum (Mazeikiene et al, 2017). The main disadvantage for more extensive use of resistance donors in breeding is the infertility of interspecific hybrids and loss of most of the resistant species' genome in multiple back‐crosses, including resistance to gall mite (Keep, 1986; Šikšnianas, Stanienė, Stanys, & Sasnauskas, 2008). Therefore, other sources of resistance are being sought.…”

Putative Genes of Pathogenesis-Related Proteins and Coronatine-Insensitive Protein 1 in Ribes spp.

“…The breeding of resistant cultivars is a top priority; however, the application of new biotechnological methods in Ribes breeding is limited by a lack of genetic knowledge and unsequenced genome [ 2 ]. To this day, only a few genes and molecular markers specific to pathogen and pest resistance have been established in some Ribes species [ 3 , 4 , 5 , 6 , 7 ]. This is why genetic mechanisms of resistance in Ribes genus are unknown, and the metabolic pathway involved in defense response after pest or pathogen infection is limited [ 8 ].…”