Outcrossing in interspecific hybrids between Eucalyptus spathulata and E. platypus

2005 ◽  
Vol 53 (4) ◽  
pp. 347 ◽  
Author(s):  
M. A. B. Wallwork ◽  
M. Sedgley

Outcrossing was investigated in interspecific hybrids between self-fertile Eucalyptus platypus Blakely and partially self-sterile E. spathulata Hook., which shows both pre- and post-zygotic timing. Four hybrid trees were used for the study, two with E. spathulata and two with E. platypus as female parent. Each hybrid had a similar number of locules to each other and to the E. platypus parent, and an intermediate number of ovules per flower compared with the parent species. Controlled hand-pollinations were carried out, in which both self- and cross-pollen from the other hybrid tree with the same female parent species was applied to flowers on each of the four trees, and observations were made 10days, 4weeks and 8weeks after pollination and at seed maturity. In all hybrids, mean seeds per capsule was consistently higher following cross-pollination than following self-pollination. All hybrids showed a reduction in pollen tube number between the top and base of the style when examined by fluorescence microscopy. One tree had significantly fewer cross- than self-pollen tubes at the base of the style, but a similar number of ovules was penetrated by pollen tubes following both treatments. In the other three, there was no difference between cross- and self-pollination in pollen tubes in the style. In three of the four trees there was no difference in ovule penetration following self- or cross-pollination, but in the other, more crossed than selfed ovules were penetrated. Light-microscopy observation of ovules indicated that ovule abortion following fertilisation accounted for the reduced numbers of seeds following self-pollination and to a lesser extent following cross-pollination. All four hybrid trees, irrespective of female parent, were partially self-sterile and resembled the partially self-sterile E. spathulata rather than the self-fertile E. platypus. While the timing of outcrossing control of E. spathulata was both pre- and post-zygotic, only one hybrid was similar, with the other three showing post-zygotic control.

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 432
Author(s):  
Yaling Chen ◽  
Benchang Hu ◽  
Fantao Zhang ◽  
Xiangdong Luo ◽  
Jiankun Xie

Dendrobium officinale is a rare and traditional medicinal plant with high pharmacological and nutritional value. The self-incompatibility mechanism of D. officinale reproductive isolation was formed in the long-term evolution process, but intraspecific hybridization of different germplasm resources leads to a large gap in the yield, quality, and medicinal value of D. officinale. To investigate the biological mechanism of self-incompatibility in D. officinale, cytological observation and the transcriptome analysis was carried out on the samples of self-pollination and cross-pollination in D. officinale. Results for self-pollination showed that the pollen tubes could grow in the style at 2 h, but most of pollen tubes stopped growing at 4 h, while a large number of cross-pollinated pollen tubes grew along the placental space to the base of ovary, indicating that the self-incompatibility of D. officinale may be gametophyte self-incompatibility. A total of 63.41 G basesum of D. officinale style samples from non-pollinated, self-pollination, and cross-pollination by RNA-seq were obtained, and a total of 1944, 1758, and 475 differentially expressed genes (DEGs) in the comparison of CK (non-pollinated) vs. HF (cross-pollination sample), CK vs. SF (self-pollination sample) and SF vs. HF were identified, respectively. Forty-one candidate genes related to self-incompatibility were found by function annotation of DEGs, including 6 Ca2+ signal genes, 4 armed repeat containing (ARC) related genes, 11 S-locus receptor kinase (SRK) related genes, 2 Exo70 family genes, 9 ubiquitin related genes, 1 fatty acid related gene, 6 amino acid-related genes, 1 pollen-specific leucine-rich repeat extensin-like protein (LRX) related gene and 1 lectin receptor-like kinases (RLKs) related gene, showed that self-incompatibility mechanism of D. officinale involves the interaction of multiple genes and pathways. The results can provide a basis for the study of the self-incompatibility mechanism of D. officinale, and provide ideas for the preservation and utilization of high-quality resources of D. officinale.


1991 ◽  
Vol 39 (4) ◽  
pp. 365 ◽  
Author(s):  
RL Goldingay ◽  
SM Schibeci ◽  
BA Walker

Experiments were carefully designed to determine the breeding system of Banksia ericifolia L.f. An equivalent percentage of flowers (78%) contained pollen tubes following self-pollination and open-pollination while a significantly smaller percentage of flowers in an autogamy treatment (44%) and cross-pollination treatment (55%) contained pollen tubes. Significantly more of the inflorescences in the open-pollination (60%) and cross-pollination (33%) treatments produced fruit compared with those in the self-pollination (11%) and autogamy treatments (13%). We suggest that B. ericifolia is largely self-incompatible because fruit production did not reflect pollen tube abundances. The influence of pollination levels on fruit production was determined by reducing the number of flowers on an inflorescence to 100 (i.e. 10% of original) or fewer and hand-pollinating these with cross pollen. There was no difference in fruit production between inflorescences with reduced flower number and open-pollinated inflorescences which had their full complement of flowers. Thus, the ability of an inflorescence to produce fruit appears more likely to be determined by the type of pollen received (cross versus self) rather than by the number of pollinated flowers it contains.


2011 ◽  
Vol 46 (11) ◽  
pp. 1480-1488 ◽  
Author(s):  
Mariane Ruzza Schuck ◽  
Luiz Antonio Biasi ◽  
Ada Michele Mariano ◽  
Bernardo Lipski ◽  
Summaira Riaz ◽  
...  

The objective of this work was to assess the potential of interspecific hybridization of Vitis labruscana and Muscadinia rotundifolia by using artificial cross-pollinations. Microsatellite markers were used to confirm interspecific hybridizations and the identity of the parental genotypes. In crosses in which M. rotundifolia was used as the female parent, no true hybrids were obtained. In the reciprocal crosses, 114 seedlings were identified as true V. labruscana x M. rotundifolia hybrids. Self pollination occurred in direct and in reciprocal crosses. The crossings between 'Bordo' x 'Carlos', 'Magnolia', 'Regale' and' Roanoke', and between' Isabel' x 'Bountiful', 'Carlos', 'Magnolia', 'Regale' and 'Roanoke' were confirmed. The 15 markers evaluated showed that two M. rotundifolia parental genotypes had the same fingerprint profile, indicating a like lyplanting error. The success of hybridization depends mainly on the species and on the cultivar used as the female parent. Microsatellite markers are efficient to confirm the paternity of interspecific F1 hybrids and to determine the correct identity of M. rotundifolia cultivars.


2019 ◽  
Vol 28 (2) ◽  
pp. 183
Author(s):  
Ni Luh Putu Indriyani ◽  
NFN Hardiyanto

<p>Bunga tanaman buah naga berukuran besar dan merupakan bunga hermaprodit yang mekar pada malam hari. Penyerbukan silang pada buah naga dapat terjadi dengan bantuan angin, serangga polinator maupun manusia. Penelitian bertujuan untuk mengetahui pengaruh teknik penyerbukan bunga betina terhadap pembuahan buah naga (Hylocereus polyrizhus). Penelitian dilakukan di Kebun Percobaan Aripan, Balai Penelitian Tanaman Tropika pada bulan Agustus sampai September 2014. Perlakuan terdiri atas: (A) penyerbukan secara alami (kontrol), (B) penyerbukan sendiri melalui isolasi bunga dengan kantong kertas minyak, (C) penyerbukan dengan mengisolasi bunga menggunakan kantong kertas minyak saat mekar pada malam hari dibantu dengan memberikan serbuk sari dari bunganya sendiri dan diisolasi kembali, dan (D) penyerbukan bunga yang didahului dengan kastrasi dan isolasi menggunakan kantong kertas minyak serta polinasi pada malam hari dan selanjutnya bunga diisolasi kembali. Setiap perlakuan terdiri atas 37 bunga tanaman buah naga. Analisis data dilakukan menggunakan uji t berpasangan pada taraf 0,05. Hasil penelitian menunjukkan bahwa teknik penyerbukan yang berbeda pada tanaman buah naga menghasilkan kelas buah yang berbeda. Persentase buah dengan kelas super tertinggi diperoleh pada penyerbukan secara alami (kontrol), meskipun persentase jadi buah paling kecil. Implikasi dari hasil penelitian ini adalah bahwa penyerbukan pada buah naga sebaiknya dilakukan secara alami tanpa menggunakan bantuan manusia.</p><p><strong>Keywords</strong></p><p>Buah naga; Penyerbukan; Pembuahan; <em>Self compatible</em></p><p><strong>Abstract</strong></p><p>The flower size of dragon fruit plants is large and a hermaphroditic nocturnal flowers. Cross pollination of the dragon fruit plants occurs because of the wind, pollinator, and humans. The aim of the research was to determine the effect of pollination technique on  fertilization of dragon fruit flowers (Hylocereus polyrizhus). This research was conducted at Aripan Experimental Field, Indonesian Tropical Fruit Research Institute (ITFRI) from August to September 2014. The treatments consisted of: (A) natural open pollination (control), (B) the flowers were isolated with paper bags and allowed to self pollination, (C) the flowers were isolated with paper bag and hand self pollinated when flowers were blooming in the evening. Furthermore all pollinated flowers were isolated with paper bag again (hand self pollination), and (D) the flowers were castrated and emasculated then they were isolated with paper bag. Cross pollination was done with pollen from the other plants. The all pollinated flowers were isolated with paper bag again (hand cross pollination). Each treatment consisted of 37 flowers of dragon fruit plants. Data were analyzed by using paired  t test 0.05. The results showed that different of pollination techniques on dragon fruit plants were produced of different fruit grade. Percentage of superior grade on natural open pollination  higher than the other treatment, even though the open pollination had smallest of percentage of  fruit set. The implication of this research is that the dragon fruit flower pollination may be done naturally without human assistance.</p>


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483f-484
Author(s):  
M.E. Lydaki ◽  
J.C. Vlahos

Ebenus cretica L., is an endemic plant of Crete with potential as a cut flower or flowering potted plant. It is a herbaceous perennial evergreen subshrub that flowers from April to June. It forms numerous thick racemes with an average of 50 pink or purple flowers 10 to 12 mm long. A great variability in major morphological characteristics exists among the populations of E. cretica on the island; however, color variants are very rare. Selection and breeding is a necessary prerequisite before the plant is marketable; therefore, research conducted at the TEI of Heraklion since 1994 has focused on artificial self- and cross-pollination of pink-flowered ebenus plants. It has been concluded that the zygomorphic flowers of E. cretica are pollinated by insects (bumblebees); the tripping mechanism occurs and seeds are formed by either cross- or self-pollination. For self-pollination, unripe flower racemes were enveloped in paper bags and shaken by hand or wind to release pollen; however, this method gave poor results. Best results were obtained by tripping the flowers while avoiding the introduction of foreign pollen. Self-incopatibility was not observed. Cross-pollination was achieved by emasculating flowers on the female parent, 2 to 4 days prior to the dehiscence of the anthers. The corolla is half-white and half-pink at this stage, turning to a uniform pink when the pollen is ripe. The stigma appears to be fully receptive at least 2 days before the dehiscence of the anthers. Each fertilized ovule gives one mature seed ≈3 weeks after pollination. This research indicates that breeding techniques can be applied without difficulty to E. cretica in order to develop uniform plant material and new varieties/hybrids with desirable characteristic.


Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Xuan Chen ◽  
Shan Hao ◽  
Li Wang ◽  
Wanping Fang ◽  
Yuhua Wang ◽  
...  

AbstractThe self-incompatibility of tea plant (Camellia sinensis (L.) O. Kuntze) was studied with the methods of aniline blue fluorescence assay and paraffin sections. The characteristics of pollen tube elongation after hand pollination was analyzed in 4 tea cultivars, including ‘Keemenzhong’, ‘Longjing-changye’, ‘Fuding-dabaicha’ and ‘Yabukita’, under self-pollination and cross-pollination, respectively. Although there were some difference among cultivars, pollen tubes elongated through the style and reach the ovary successfully at 48 h after pollination for both cross- and self-pollen tubes in all the four cultivars of tea. Pollen tubes entered into the ovule micropyles, however, only for cross-pollination, but not for self-pollination. Pollen tubes of selfing plants, failed in fertilizing, seemed have some difficulties to enter the ovule. All of which indicated that the self-incompatibility of tea plant is a late-acting self-incompatibility system (LSI) or an ovarian sterility (OS), in which the self incompatibility was due to none self pollen tube penetrating into the ovule and no fertilization.


2002 ◽  
Vol 50 (3) ◽  
pp. 365 ◽  
Author(s):  
L. M. Pound ◽  
M. A. B. Wallwork ◽  
B. M. Potts ◽  
M. Sedgley

Controlled pollinations with self- and cross-pollen were applied to individual flowers of five mature Eucalyptus globulus Labill. ssp. globulus trees to investigate the site of action of the self-incompatibility mechanism. Growth of pollen tubes in styles at 2 weeks after pollination and ovule penetration by pollen tubes at 2 and 4 weeks after pollination were investigated by fluorescence microscopy. Some pollinated flowers were left to develop to seed maturity, then harvested to quantify the level of self-incompatibility of each tree. Trees ranged from 76 to 100% self-incompatible. There was no significant difference in the number of pollen tubes in the style between treatments although variation was present between trees. The number of pollen tubes present was similar to the number of ovules present within flowers. Penetration of ovules by pollen tubes over all five trees combined revealed no difference between treatments at 2 weeks after pollination; however, there was slightly greater penetration by cross-pollen tubes at 4 weeks after pollination. This difference was not large enough to account for the near complete lack of selfed-seed production, suggesting late pre- or post-zygotic arrest of selfed ovules.


1996 ◽  
Vol 44 (6) ◽  
pp. 661 ◽  
Author(s):  
M Sedgley ◽  
L Granger

Embryology of Eucalyptus spathulata Hook. and E. platypus Hook. (subgenus Symphyomyrtus, section Bisectaria) was investigated by bright field microscopy to determine the cause of ovule failure at 2 months following selfing, crossing and reciprocal interspecific pollination. Eucalyptus spathulata retained more capsules and produced more seeds following cross- than self-pollination, whereas there was no difference between selfing and crossing for E. platypus. Both species produced seeds following interspecific pollination, but germination was low. Highest ovule penetration by a pollen tube, and ovule growth at 2 months, was observed following crossing of E. spathulata and following interspecific pollination of E. platypus. Most self-pollinated ovules of both species were degenerating and were either unfertilised or had undivided zygotes and free nuclear endosperm. Muticellular pro-embryos were more common in cross-pollinated and interspecific pollinated ovules than following selfing. It was concluded that ovule degeneration of E. spathulata and E. platypus following selfing resulted from low levels of pollen tube penetration and fertilisation, and that in those ovules which were fertilised, the zygote generally failed to divide. Degeneration following cross-pollination of E. spathulata also resulted from failure of the zygote to divide, and in E. platypus additional reasons were low levels of pollen tube penetration and fertilisation, and lack of cellularisation of the endosperm. Ovule degeneration of both species following interspecific pollination included failure of the zygote to divide, but in E. spathulata it also resulted from slower embryo development and reduced cellularisation of the endosperm.


2003 ◽  
Vol 51 (2) ◽  
pp. 189 ◽  
Author(s):  
L. M. Pound ◽  
B. Patterson ◽  
M. A. B. Wallwork ◽  
B. M. Potts ◽  
M. Sedgley

This study investigated whether pollen competition favours cross- over self-pollination in Eucalyptus globulus Labill. ssp. globulus. Controlled pollinations with self-pollen, cross-pollen and a mixture of self- and cross-pollen were conducted on three partially self-incompatible trees. The paternity of individual seeds resulting from mixed pollination was determined by isozyme analysis. No evidence for pollen competition was found. Instead, seed paternity reflected the level of self-incompatibility of each tree as determined by separate self- and cross-pollinations. Furthermore, the number of seeds set per capsule following mixed pollination was significantly less than that following cross-pollination in the two least self-compatible trees. These results suggest that both self- and cross-pollen tubes reach ovules following mixed pollination and that a late-acting self-incompatibility mechanism operates to abort a certain proportion of self-penetrated ovules.


2017 ◽  
Vol 1 ◽  
pp. 347
Author(s):  
H. Bendif, R. Benmehia ◽  
F. Bahlouli, S. Tellache, A. Slamani A. Zedam

The present work consists in contributing to the study of pollination. Field observations and tests were carried out on six varieties of apricot in the region of M'sila, "Pavit", "Boulida" "Alarbi","Tounsi","Ben sarmouk" and "Louzi rouge". For natural self-pollination, the branches were covered to avoid cross-pollination, and the fruit set was determined. Controlled pollination was carried out using pollen and pollen from the other trees that bloom at about the same time. The fruit set rate was determined after counting the fruits in relation to the number of blooming flowers. The rate of fruit set varies from one variety to another. Alarbi with 62.5%, Louzi with 69.7%, Tounssi with 56.5%, Bulida with 50.7%, Ben Sermouk with 23.2% and Pavit with 45.8%. The bagging rate of the bagged branch obtained at the end of the physiological fall did not show any significant differences between the varieties and ranged between 77.50% for Alarbi and 41.22% for Pavit. The results show that the number of fruits after manual crossing is zero for all crops. All varieties tested are self-compatible and no cross-compatibility group has been guessed on the tested growths, from self-pollination and inter-pollination.


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