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
Rafel Socias i Company, Àngel Fernández i Martí, Ossama Kodad and José M. Alonso
Reut Niska, Martin Goldway and Doron Schneider
, 2000 ). However, some loquat cultivars such as ‘Akko 1’, ‘Mogi’, ‘Pale Yellow’, ‘Advance’, and ‘Tanaka’ are self-fertile or partially self-fertile ( Cuevas et al., 2003 ; Morton, 1987 ; Tous and Ferguson, 1996 ). In the Maloideae subfamily, self-compatibility
Ossama Kodad, Rafel Socias i Company, Ana Sánchez and M. Margarida Oliveira
the origin of self-compatibility in almond. It has been suggested that SC in almond could be explained by quantifying the transcript expression of the S -RNases in the style. Watari et al. (2007) reported that the low transcriptional level of the
Chitose Honsho, Masami Kotsubo, Yuri Fukuda, Yosui Hamabata, Yoshikazu Kurogi, Aya Nishiwaki and Takuya Tetsumura
pollination in this study. Discussion Self-compatibility in ‘Nishiuchi Konatsu’. Hyuganatsu cannot produce fruits by self-pollination as a result of its self-incompatible nature ( Miwa, 1951 ). On the other hand, ‘Nishiuchi Konatsu’, a bud mutation of
Ryutaro Tao, Tsuyoshi Habu, Hisayo Yamane, Akira Sugiura and Kazuya Iwamoto
Self-compatible cultivars of Japanese apricot (Prunus mume Sieb. et Zucc.) have a horticultural advantage over self-incompatible ones because no pollinizer is required. Self-incompatibility is gametophytic, as in other Prunus species. We searched for molecular markers to identify self-compatible cultivars based on the information about S-ribonucleases (S-RNases) of other Prunus species. Total DNA isolated from five self-incompatible and six self-compatible cultivars were PCR-amplified by oligonucleotide primers designed from conserved regions of Prunus S-RNases. Self-compatible cultivars exhibited a common band of ≈1.5 kbp. Self-compatible cultivars also showed a common band of ≈12.1 kbp when genomic DNA digested with HindIII was probed with the cDNA encoding S 2-RNase of sweet cherry (Prunus avium L.). These results suggest that self-compatible cultivars of Japanese apricot have a common S-RNase allele that can be used as a molecular marker for self-compatibility.
Sandra M. Reed
Clethra alnifolia, which is commonly known as summersweet, is an attractive deciduous shrub that produces fragrant flower in mid-summer. Breeding efforts are hampered by a lack of information on the reproductive behavior of this native species. The objective of this study was to evaluate self-compatibility in C. alnifolia. Pollen germination and pollen tube growth in styles were examined following self- and cross-pollinations using fluorescence microscopy. Seed set and germination were compared following self- and cross-pollinations. While self-pollen tubes appeared to grow slightly slower than cross-pollen tubes, there was no indication of a self-incompatibility system acting at the stigmatic or stylar level in C. alnifolia. Self-pollinations of `Hummingbird' and `Ruby Spice' produced fewer seeds than did cross-pollinations of these cultivars. Germination of all seed obtained from this study was too poor to allow a comparison of germination rates of the self- and cross-pollinated seed. However, because a few self-progeny were obtained, emasculation is recommended when making controlled pollinations. The presence of a late-acting self-incompatibility system or early acting inbreeding depression was proposed as being responsible for the lower seed set following self-pollination.
Akiko Watari, Toshio Hanada, Hisayo Yamane, Tomoya Esumi, Ryutaro Tao, Hideaki Yaegaki, Masami Yamaguchi, Kenji Beppu and Ikuo Kataoka
., 2003 ; Yamane et al., 2003c ), and apricot ( Romero et al., 2004 ). The results from these studies have led to the development of not only molecular typing methods for S -haplotypes ( Tao et al., 1999 ), but also molecular markers for self-compatibility
Daniel J. Bell, Lisa J. Rowland, John Stommel and Frank A. Drummond
Two types of field hand crosses (pairwise touching-neighbor and a full 5 × 5 diallel, Griffing's Model 2, Method 3) were performed in combination with genetic similarity estimations of mating partners using expressed sequence tag–polymerase chain reaction molecular markers to elucidate genetic factors underlying yield variations among clones (genotypes) of lowbush blueberry (Vaccinium angustifolium) in two managed fields in Maine. Genetic similarity values for touching pairs ranged from 0.308 to 0.765. Based on pairwise touching-neighbor crosses, no evidence was found for yield being affected by genetic similarity. However, self-fertility of clones was a significant positive predictor of outcross yields. The calculation of lethal equivalents, derived from selfing to outcross ratios, showed a large range in genetic load among clones and a higher average load than that previously reported in the related highbush blueberry (V. corymbosum). The diallel experiment revealed significant general and specific combining ability for all three post-pollination yield traits measured (proportion fruit set, mean mature seed per pollination, and mean berry weight per pollination). Narrow-sense heritability estimates for all three yield traits were moderately high (h2 = 0.58, 0.46, and 0.56, respectively). It is concluded that phenotypically screening for self-compatible clone yield attributes could be useful in identifying germplasm candidates for breeding and propagation.
Alan T. Whittemore and Alden M. Townsend
Artificial cross-pollinations were carried out among seven species of Celtis L. (C. bungeana Blume, C. koraiensis Nakai, C. laevigata Willd., C. occidentalis L., C. reticulata Torr., C. sinensis Pers., and C. tenuifolia Nutt.) to test the potential for interspecific hybridization in Celtis breeding. AFLP profiles were used to assess the ancestry of progeny. Hybrids formed very rarely among these seven species of Celtis: only two interspecific hybrids were obtained. Self-pollination occurred occasionally in non-emasculated trees. AFLP analysis yielded false paternal markers at a very low frequency, likely due to DNA methylation differences. Plants with unexpected paternal markers were confidently distinguished from hybrids by calculating the probability of obtaining the observed number of paternal markers by chance. The study clearly demonstrated the importance of using large numbers of markers.
Tsuyoshi Habu, Fumio Kishida, Miki Morikita, Akira Kitajima, Toshiaki Yamada and Ryutaro Tao
Japanese apricot (Prunus mume Sieb. et Zucc.) exhibits S-RNase-based gametophytic self-incompatibility as do other Prunus species. Both self-incompatible and self-compatible Japanese apricot cultivars are grown commercially in Japan. These self-compatible cultivars are shown to have a common S-haplotype called S f that contains S f-RNase and SFB f (S-haplotype-specific F-box protein). This study describes a simple and rapid detection of SFB f, in Japanese apricot, based on loop-mediated isothermal amplification (LAMP) method. A set of 4 primers, F3, B3, FIP, and BIP primer, were designed from the exon and the putative inserted sequence of SFB f. Optimal reaction time at 63 C was determined to be 90 minutes. It appeared that the LAMP method combined with the ultrasimple DNA extraction efficiently detected SFB f. The advantage of the marker-assisted selection of self-compatibility based on the LAMP method was discussed.