Embryology of Eucalyptus Spathulata and E. platypus (Myrtaceae) Following Selfing, Crossing and Reciprocal Interspecific Pollination

1996 ◽  
Vol 44 (6) ◽  
pp. 661 ◽  
Author(s):  
M Sedgley ◽  
L Granger
Keyword(s):  
Pollen Tube ◽  
Embryo Development ◽  
Bright Field ◽  
Cross Pollination ◽  
Self Pollination ◽  
Bright Field Microscopy ◽  
Low Levels ◽  
Pollen Tube Penetration ◽  
Ovule Penetration

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.

Fruit Development of Pistacia vera (Anacardiaceae) in Relation to Embryo Abortion and Abnormalities at Maturity

1996 ◽  
Vol 44 (1) ◽  
pp. 35 ◽  
Author(s):  
YD Shuraki ◽  
M Sedgley
Keyword(s):  
Pollen Tube ◽  
Fruit Development ◽  
Embryo Sac ◽  
Vascular Bundles ◽  
Pistacia Vera ◽  
Bright Field ◽  
Embryo Abortion ◽  
Common Cause ◽  
Bright Field Microscopy ◽  
Pollen Tube Penetration

This study investigated fruit development of the Pistacia vera L. cultivars Kerman and Sirora using bright field microscopy. Normal fruit development was compared with that of seedless (blank) and small seeded (semi-blank) fruits to identify the stages at which degeneration occurred. In normal fruits, pericarp growth took place up to week 4 after pollination and preceded embryo, endosperm and funicle proliferation between weeks 4 and 16. Endocarp (shell) and exocarp (hull) development occurred between weeks 8 and 16. Blank and semi-blank fruits were identified by slower growth and lack of exocarp colouration. Blank fruits resulted from one of five patterns of ovule degeneration caused by funicle degeneration, embryo sac absence, embryo sac degeneration, lack of pollen tube penetration of the embryo sac, or failure of endosperm cellularisation. Funicle degeneration was the most common cause of blanking and was observed either at the site of pollen tube penetration or at the chalazal end of both pollinated and unpollinated ovules. Degeneration of funicular tissue extended towards the vascular bundles. Small seeded or semi-blank fruit resulted from degeneration of the cotyledons during the latter stage of embryo development.

scholarly journals Transcriptomic Analysis Reveals a Comprehensive Calcium- and Phytohormone-Dominated Signaling Response in Leymus chinensis Self-Incompatibility

2019 ◽  
Vol 20 (9) ◽  
pp. 2356 ◽  
Author(s):  
Shuangyan Chen ◽  
Junting Jia ◽  
Liqin Cheng ◽  
Pincang Zhao ◽  
Dongmei Qi ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Tube Growth ◽  
Leymus Chinensis ◽  
Self Incompatibility ◽  
Cross Pollination ◽  
Grass Family ◽  
Self Pollination

Sheepgrass (Leymus chinensis (Trin.) Tzvel.) is an economically and ecologically important forage in the grass family. Self-incompatibility (SI) limits its seed production due to the low seed-setting rate after self-pollination. However, investigations into the molecular mechanisms of sheepgrass SI are lacking. Therefore, microscopic observation of pollen germination and pollen tube growth, as well as transcriptomic analyses of pistils after self- and cross-pollination, were performed. The results indicated that pollen tube growth was rapidly inhibited from 10 to 30 min after self-pollination and subsequently stopped but preceded normally after cross-pollination. Time course comparative transcriptomics revealed different transcriptome dynamics between self- and cross-pollination. A pool of SI-related signaling genes and pathways was generated, including genes related to calcium (Ca2+) signaling, protein phosphorylation, plant hormone, reactive oxygen species (ROS), nitric oxide (NO), cytoskeleton, and programmed cell death (PCD). A putative SI response molecular model in sheepgrass was presented. The model shows that SI may trigger a comprehensive calcium- and phytohormone-dominated signaling cascade and activate PCD, which may explain the rapid inhibition of self-pollen tube growth as observed by cytological analyses. These results provided new insight into the molecular mechanisms of sheepgrass (grass family) SI.

Outcrossing in interspecific hybrids between Eucalyptus spathulata and E. platypus

2005 ◽  
Vol 53 (4) ◽  
pp. 347 ◽  
Author(s):  
M. A. B. Wallwork ◽  
M. Sedgley
Keyword(s):  
Interspecific Hybrids ◽  
Female Parent ◽  
Pollen Tubes ◽  
The Other ◽  
Parent Species ◽  
Cross Pollination ◽  
Seed Maturity ◽  
Self Pollination ◽  
Ovule Penetration ◽  
Zygotic Control

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.

Pollen Tube Growth and Early Seed Development in Eucalyptus regnans F. Muell. (Myrtaceae) in Relation to Ovule Structure and Preferential Outcrossing

1989 ◽  
Vol 37 (5) ◽  
pp. 397 ◽  
Author(s):  
M Sedgley ◽  
FC Hand ◽  
RM Smith ◽  
AR Griffin
Keyword(s):  
Pollen Tube ◽  
Phase Contrast ◽  
Pollen Tubes ◽  
Central Canal ◽  
Transmitting Tissue ◽  
Bright Field ◽  
Eucalyptus Regnans ◽  
Cross Pollination ◽  
Early Seed Development ◽  
Scanning Electron

Pistils of Eucalyptus regnans were observed by bright field, fluorescence, phase contrast, Nomarski, and scanning electron microscopy from 4 weeks prior to anthesis to 16 weeks after self- and cross- pollination. The transmitting tissue of the style had a central canal which extended for half its length. The unfertilised ovary contained a mean of 30.5 ovular structures with 16.5 normal ovules, 2.5 abnor- mal ovules, and 11.5 sterile ovulodes. The ovules were arranged in two rows in three (occasionally four) locules. The ovulodes always occupied positions at the stylar end of the ovary, but with this exception there was no pattern to the occurrence of the abnormal ovules. Pollen tubes grew between the cells'of the transmitting tissue, and not in the stylar canal. Penetration of the ovules had commenced by 5 days after both self- and cross-pollination. The early fertilised ovule contained a zygote and free-nuclear endosperm, and embryos with between 1 and 16 cells were present at 16 weeks after pollination. Not all normal ovules were fertilised, despite adequate numbers of pollen tubes. Ovulodes were never observed to be penetrated by a pollen tube, but with this exception there was no relationship between position on the placenta and either the penetration of ovules by a pollen tube or the occurrence of fertilised ovules. There was no difference between self- and cross-pollination in either the number of ovules penetrated by a pollen tube, or the number of fertilised ovules up to 16 weeks following pollination.

scholarly journals Reciprocal intercompatibility between Byrsonima Rich. exKunth species (Malpighiaceae), in an urban ecotonal fragment of Semi-Deciduous Seasonal Forest and Cerrado

2021 ◽  
pp. 211-221
Author(s):  
Frederic Mendes Hughes
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Prezygotic Isolation ◽  
Stigmatic Surface ◽  
Cross Pollination ◽  
Self Pollination ◽  
Isolation Mechanisms ◽  
Hypothesis Evaluation

Byrsonima species present floral monomorphism and sharing visitor/pollinator guild. These traits suggest the hypothesis evaluation of reciprocal inter-incompatibility between two syntopic Byrsonima species: B. pachyphylla and B. crassifolia. Pollen tube growth with similar behavior was observed in the stigmatic surface, pistil canal, ovary and micropylar channel to both species. In addition, partial self-incompatibility in self-pollination with greater fruiting in autogamy was observed. Cross-pollination and self-pollination coexist, and reciprocal intercompatibility occurs. Prezygotic isolation mechanisms are unlikely by the absence of abnormal pollen tubes, higher fruiting production and absence of hybrids in the study site. Las especies de Byrsonima presentan monomorfismo floral y comparten gremio de visitantes/polinizadores. Estos rasgos sugieren la evaluación de hipótesis de interincompatibilidad recíproca entre dos especies sintópicas de Byrsonima: B. pachyphylla y B. crassifolia. Se observó el crecimiento del tubo polínico con comportamiento similar en la superficie estigmática, canal del pistilo, ovario y canal micropilar de ambas especies. Además, se describió la autoincompatibilidad parcial en la autopolinización con mayor fructificación en la autogamia. La polinización cruzada y la autopolinización coexisten y se produce una intercompatibilidad recíproca. Los mecanismos de aislamiento precigóticos son improbables por la ausencia de tubos polínicos anormales, producción de frutos y ausencia de híbridos en la área de estudio.

scholarly journals Comparison of different classical and molecular methods for identifying self-incompatibility in two olive cultivars

2019 ◽  
Vol 17 (3) ◽  
pp. e0804 ◽  
Author(s):  
Elham Aslmoshtaghi ◽  
Ali Reza Shahsavar ◽  
Majid Talebi ◽  
Aziz Dazeh
Keyword(s):  
Pollen Tube ◽  
Molecular Analysis ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Research Station ◽  
Self Incompatibility ◽  
Controlled Pollination ◽  
Cross Pollination ◽  
Self Pollination ◽  
Olive Cultivars

Aim of study: To determine compatibility relationships and select suitable pollinizers for two olive (Olea europaea L.) cultivars (‘Amygdalolia’ and ‘Konservalia’).Area of study: The Kazeroun Olive Research Station, Fars, Iran.Material and methods: Emasculated flowers from ‘Amygdalolia’ and ‘Konservalia’ cultivars were treated with self-pollination, open-pollination, and cross-pollination with pollen from cultivars such as ‘Dacal’, ‘Amygdalolia’,‘Konservalia’, ‘Koroniki’, and ‘Manzanilla’. Controlled pollination, pollen tube growth, and molecular analysis were employed.Main results: Controlled pollination, pollen tube growth, and molecular analysis showed that cross-pollination was beneficial for ‘Amygdalolia’ compared to self-pollination. The results showed that this cultivar is self-incompatible, and its best pollinator is the ‘Dacal’ cultivar. Experiment results indicated that ‘Konservalia’ behaves as a self-compatible cultivar. The highest fruit percentage and higher pollen tube growth rates were found in self-pollination treatments. Molecular attempts to isolate candidates for sporophytic self-incompatibility (SSI) led the researchers to analyze the expression of SRK and SLG genes.Research highlights: The results indicated an antagonist transcriptional expression pattern in the flowers of ‘Amygdalolia’, classified as a self-incompatible cultivar, and ‘Konservalia’, classified as a self-compatible cultivar, for the SRK and SLG genes.

Late-acting self-incompatibility in tea plant (Camellia sinensis)

Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Xuan Chen ◽  
Shan Hao ◽  
Li Wang ◽  
Wanping Fang ◽  
Yuhua Wang ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Camellia Sinensis ◽  
Pollen Tubes ◽  
Tea Plant ◽  
The Self ◽  
Self Incompatibility ◽  
Cross Pollination ◽  
Self Pollination ◽  
Hand Pollination ◽  
Pollen Tube Elongation

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.

scholarly journals Effect of self-pollination with heat-treated pollen on parthenocarpy and homozygosity in cassava

1970 ◽  
Vol 28 (3) ◽  
pp. 449-472
Author(s):  
M. Buttibwa ◽  
R.S. Kawuki ◽  
J.K. Baguma ◽  
P. Nalela ◽  
M. Eyokia ◽  
...  
Keyword(s):  
Plant Regeneration ◽  
Pollen Tube ◽  
Genetic Improvement ◽  
Fruit Set ◽  
Plant Production ◽  
Egg Cell ◽  
Polymorphism Analysis ◽  
Self Pollination ◽  
Heat Treated ◽  
Pollen Tube Penetration

Cassava’s (Manihot esculenta Crantz) high heterozygosity complicates its genetic improvement via selective breeding. Double haploid (DH) technology can be used to improve the crop’s heterozygosity, thereby improving the capacity for genetic improvement. The objective of this study was to evaluate the effect of self-pollination using heated pollen on pollen tube penetration, fruit set, seed and haploid embryo development in cassava genotypes for the production of haploid cassava. Pollen from two cassava genotypes, NASE3 and NASE14, was heated at 40, 50 and 60 oC for 0.5, 1.0 and 2.0 hr each. The heated pollen was used in six rounds of self-pollinations. Pollen tube penetration was monitored by fluorescent microscopy, followed by early embryo rescue and ovule culture. Ploidy and zygosity were assessed using flow cytometry and single-nucleotide polymorphism analysis, respectively. Pollen germinated on the stigma, grew within the style through the nucellar beak, but did not reach the embryo sac, thus achieving no fertilisation in all the 5756 self-pollinated flowers. There was a reduction in pollen germination (in vitro and in vivo), pollen tube penetration and fruit set with increasing temperature. Heat-treated pollen stimulated division of the egg cell and induced development of parthenocarpic fruits. Up to 6 embryoids per ovule were observed and all regenerated plantlets were diploid, with up to 93.0% increased homozygosity. For the first time, plant regeneration from ovules, pollinated with fresh pollen at 14 days after pollination, was achieved indicating improved speed in plant regeneration. The data generated are important for the development of protocols for cassava DH plant production.

scholarly journals An Evaluation of Fertility in Arkansas Primocane-fruiting Blackberries

HortScience ◽  
2010 ◽  
Vol 45 (7) ◽  
pp. 1000-1005 ◽  
Author(s):  
Alisha L. Ruple ◽  
John R. Clark ◽  
M. Elena Garcia
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Fruit Set ◽  
Pollen Viability ◽  
Tube Growth ◽  
Stigma Receptivity ◽  
Cross Pollination ◽  
Self Pollination ◽  
Selection Of

Floral fertility of five primocane-fruiting (PF) blackberry (Rubus L. subgenus Rubus Watson) genotypes (‘Prime-Jim’®, APF-31, ‘Prime-Ark® 45’, APF-59, and APF-77) and three floricane-fruiting (FF) genotypes (‘Navaho’, ‘Natchez’, and ‘Ouachita’) were tested under field conditions using floricane flowers with four pollination treatments: undisturbed open-pollinated, emasculated self-pollinated, emasculated and cross-pollinated with pollen from a similar fruiting type (PF × PF or FF × FF), and emasculated and cross-pollinated with pollen from a different fruiting type (PF × FF or FF × PF). During primocane flowering, three pollination treatments (undisturbed open-pollinated, emasculated selfed, and emasculated cross-pollinated) were used to further test the fertility of the five PF genotypes. Significant differences between cross-pollination treatments and self-pollination were seldom noted with more differences seen in ‘Prime-Jim’® than any other genotype. Cross-pollinating primocane flowers on ‘Prime-Jim’® resulted in significantly higher fruit set, drupelet set, and average berry weight compared with self-pollination. Fruit set among genotypes ranged from 68.5 to 96.7%, and drupelet set rating ranged from 4.3 to 6.9 for floricane flowers. For open-pollinated primocane flowers, fruit set ranged from 63.9 to 92.1%, and drupelet set rating ranged from 4.3 to 7.2. The genotypes APF-31, APF-59, and APF-77 showed a marked improvement over ‘Prime-Jim’® in both percent fruit set and drupelet set of floricane and primocane flowers. The results indicated that fertility appears to be sufficient in all the genotypes evaluated and that the later-generation PF genotypes show improvement in fertility over ‘Prime-Jim’®. Pollen viability (using both chemical viability testing and in vitro germination testing), stigma receptivity, and pollen tube growth (using florescence) were evaluated in a controlled environment to determine if any improvements could be noticed when comparing a selection of later-generation PF genotypes (APF-31,' Prime-Ark® 45', APF-59, and APF-77) with ‘Prime-Jim’® and ‘Prime-Jan’®. Genotypes APF-31, APF-59, and APF-77 had significantly more viable pollen and pollen germination than ‘Prime-Jan’®. Stigma receptivity was observed in all genotypes. Pollen tube growth did not appear to be inhibited after self-pollination in any genotype studied, although significantly greater florescence resulting from pollen tube growth was seen after cross-pollination compared with self-pollination for APF-59. There were no significant differences in pollen tube growth between cross- and self-pollination for any other genotype.

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