How Have Self-Incompatibility Haplotypes Diversified? Generation of New Haplotypes during the Evolution of Self-Incompatibility from Self-Compatibility

2016 ◽  
Vol 188 (2) ◽  
pp. 163-174 ◽  
Author(s):  
Satoki Sakai
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ling Ma ◽  
Chunzhi Zhang ◽  
Bo Zhang ◽  
Fei Tang ◽  
Futing Li ◽  
...  

AbstractPotato is the third most important staple food crop. To address challenges associated with global food security, a hybrid potato breeding system, aimed at converting potato from a tuber-propagated tetraploid crop into a seed-propagated diploid crop through crossing inbred lines, is under development. However, given that most diploid potatoes are self-incompatible, this represents a major obstacle which needs to be addressed in order to develop inbred lines. Here, we report on a self-compatible diploid potato, RH89-039-16 (RH), which can efficiently induce a mating transition from self-incompatibility to self-compatibility, when crossed to self-incompatible lines. We identify the S-locusinhibitor (Sli) gene in RH, capable of interacting with multiple allelic variants of the pistil-specific S-ribonucleases (S-RNases). Further, Sli gene functions like a general S-RNase inhibitor, to impart SC to RH and other self-incompatible potatoes. Discovery of Sli now offers a path forward for the diploid hybrid breeding program.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jianbing Hu ◽  
Qiang Xu ◽  
Chenchen Liu ◽  
Binghao Liu ◽  
Chongling Deng ◽  
...  

AbstractSelf-incompatibility (SI) substantially restricts the yield and quality of citrus. Therefore, breeding and analyzing self-compatible germplasm is of great theoretical and practical significance for citrus. Here, we focus on the mechanism of a self-compatibility mutation in ‘Guiyou No. 1’ pummelo (Citrus maxima), which is a spontaneous mutant of ‘Shatian’ pummelo (Citrus maxima, self-incompatibility). The rate of fruit set and the growth of pollen tubes in the pistil confirmed that a spontaneous mutation in the pistil is responsible for the self-compatibility of ‘Guiyou No. 1’. Segregation ratios of the S genotype in F1 progeny, expression analysis, and western blotting validated that the reduced levels of S2-RNase mRNA contribute to the loss of SI in ‘Guiyou No. 1’. Furthermore, we report a phased assembly of the ‘Guiyou No. 1’ pummelo genome and obtained two complete and well-annotated S haplotypes. Coupled with an analysis of SV variations, methylation levels, and gene expression, we identified a candidate gene (CgHB40), that may influence the regulation of the S2-RNase promoter. Our data provide evidence that a mutation that affects the pistil led to the loss of SI in ‘Guiyou No. 1’ by influencing a poorly understood mechanism that affects transcriptional regulation. This work significantly advances our understanding of the genetic basis of the SI system in citrus and provides information on the regulation of S-RNase genes.


1980 ◽  
Vol 28 (4) ◽  
pp. 437 ◽  
Author(s):  
P Bernhardt ◽  
RB Knox ◽  
DM Calder

Facultative cleistogamy has not been found In some Austrahan Amyema spp , and the stigma does not functlon in pollen presentation at anthesis. Wlthin mature flower buds self-polllnatlon is prevented by morphological and physiological barriers, a protandrous condition largely prevents mechanical or zoophilous self-pollination In vitro pollination experiments revealed that xenogamous crosses are most successful In the production of pollen tubes in the style although geitonogamy may act as a 'fail safe mechanism' at varying levels under natural condltlons in A miquelii (Lehm, ex Miq) Van Tiegh, A. miraculosum (Miq ) Van Tiegh and A. penduium (Sieber ex Spreng ) Van Tiegh. Of the four species studied, A. quandang (Lindl ) Van Tiegh had the highest levels of self-compatibility.


1986 ◽  
Vol 28 (5) ◽  
pp. 796-807 ◽  
Author(s):  
J. S. Shore ◽  
S. C. H. Barrett

Diploid and tetraploid populations of Turnera ulmifolia are distylous and exhibit a strong self-incompatibility system. Distyly is governed by a single locus with two alleles. Several self-compatible variants were, however, obtained and the nature and genetic control of self-compatibility was assessed using controlled crosses. The study documented the occurrence of self-compatible variants in four contrasting situations. These included the following. (i) Self-compatibility in a diploid short-styled variant. The gene(s) governing self-compatibility interact with the distyly locus and are expressed only in short-styled plants. When tetraploids carrying the genes were synthesized, self-incompatibility reappeared. (ii) Self-compatibility occurred in a cross between geographically separate diploid populations. Self-compatibility appeared sporadically in the F1. Crosses revealed that self-compatibility is likely under polygenic control. (iii) Low levels of self-compatibility occurred in a tetraploid population. Crosses revealed that self-compatibility was under polygenic control. A small response to selection for increased self-compatibility was observed, (iv) Hexaploids were synthesized from crosses between distylous diploids and tetraploids. All hexaploids obtained were long- or short-styled indicating that hexaploidy per se does not cause homostyly. A single long-styled plant showed aberrant pollen behaviour, resulting in a moderate degree of self-compatibility. All of the variants studied exhibited either aberrant pollen or stylar incompatibility responses. In no instance was the genetic control of self-compatibility solely the result of segregation at the distyly locus.Key words: Turnera, dimorphic incompatibility, polyploidy, self-compatibility, distyly.


1987 ◽  
Vol 65 (4) ◽  
pp. 660-665 ◽  
Author(s):  
S. P. Vander Kloet ◽  
P. M. Lyrene

The results of self-pollinations, sibling pollinations, and cross-pollinations were compared in terms of number of berries produced per 100 pollinated flowers, number of plump seeds per berry, percent seed germination, and time between pollination and fruit ripening. The population studied consisted of 344 Vaccinium corymbosum L. seedlings grown from seeds harvested from native populations at 26 sites extending from Florida to Nova Scotia. Diploid, tetraploid, and hexaploid plants were included in the study, but only homoploid crosses were made in order to avoid the confounding effect of the strong heteroploid crossing barriers in V. corymbosum. Self-pollinations resulted in great reductions in all fertility parameters. Sibling pollinations produced far fewer seedlings than cross-pollinations, mainly because the number of plump seeds per berry was reduced from an average of 21 for outcrosses to 13 for sibling crosses. Pollination with 1:1 mixtures of self and outcross pollen reduced plump seed number per berry to 5, compared with 14 for comparable outcrosses. The results were similar at all three ploidy levels. It is concluded that self-compatibility is low in natural populations of V. corymbosum.


Sign in / Sign up

Export Citation Format

Share Document