scholarly journals Selective fertilization in interspecific crosses of allotetraploid species of Gossypium

Botany ◽  
2012 ◽  
Vol 90 (3) ◽  
pp. 159-166 ◽  
Author(s):  
G.S. Pereira ◽  
R.L. Sousa ◽  
R.L. Araújo ◽  
L.V. Hoffmann ◽  
E.F. Silva ◽  
...  

The genus Gossypium is composed of both diploid and allotetraploid species. The five allotetraploid species of Gossypium are sexually compatible, and only partial sexual barriers have been described. Natural hybrids among them do not occur or occur in situ with very low frequency in Brazil in the rare places where cultivated upland cotton ( Gossypium hirsutum L.) occurs in a sympatric range with Gossypium barbadense L. or Gossypium mustelinum Miers. We evaluated the presence of pollen competition as a prezygotic barrier in crosses between upland cotton and G. barbadense and G. mustelinum. We found that G. barbadense pollinated with a mixture of 50% upland cotton and 50% G. barbadense pollen resulted in 17.4%–31.1% interspecific hybrids, depending upon the upland cotton genotype used as pollen donor. Mixtures containing pollen from G. mustelinum and upland cotton, used to pollinate G. mustelinum in proportions of 25%:75%, 50%:50%, and 75%:25%, produced 61.3%, 22.5%, and 3.6% interspecific hybrids, respectively. These low rates of hybrid production demonstrate that pollen competition is present with G. mustelinum and G. barbadense and confirms this mechanism as a sexual barrier.

Genome ◽  
2003 ◽  
Vol 46 (3) ◽  
pp. 469-472 ◽  
Author(s):  
A Benabdelmouna ◽  
G Guéritaine ◽  
M Abirached-Darmency ◽  
H Darmency

Genomic in situ hybridization (GISH) applied to the F1 interspecific hybrid between oilseed rape (Brassica napus, AACC, 2n = 38) and wild radish (Raphanus raphanistrum, RrRr, 2n = 18) showed the predicted 19 chromosomes from B. napus and 9 chromosomes from R. raphanistrum. The very low female fertility of these interspecific hybrids when backcrossed to R. raphanistrum led to only two descendants. Their chromosome number varied between 45 and 48. Both of these progenies showed only 9 chromosomes from R. raphanistrum and 36–39 chromosomes from B. napus. These results indicate the efficiency and limits of GISH as a suitable tool to assess and interpret the behavior of chromosomes after such interspecific crosses. The unexpected chromosome combination is discussed.Key words: genomic in situ hybridization, interspecific hybrid, introgression, oilseed rape, wild radish.


1986 ◽  
Vol 64 (2) ◽  
pp. 282-291 ◽  
Author(s):  
V. Kaul ◽  
J. L. Rouse ◽  
E. G. Williams

Early events in the embryo sac of Rhododendron kawakamii and R. retusum have been studied after compatible self-pollinations and eight interspecific crosses, using sectioned ovaries, pistil squashes, and seed-set data. Ovules of Rhododendron kawakamii and R. retusum are anatropous, unitegmic, and tenuinucellate, with a typical eight-nucleate, seven-celled embryo sac. Fertilization normally occurs 4–5 days after pollination. The zygote lays down a callose wall but remains undivided during the first 13–15 days after pollination. The primary endosperm nucleus divides soon after fertilization, and development is cellular ab initio. Crosses of R. kawakamii (♂) with R. santapaui and R. retusum and crosses of R. retusum (♂) with R. kawakamii, R. santapaui, R. ovatum, and R. tashiroi showed apparently normal fertilization in a majority of ovules entered by pollen tubes. In crosses of R. kawakamii (♂) with R. quadrasianum and Kalmia latifolia entry of pollen tubes into ovules was delayed and frequently abnormal. Apart from compatible self-pollinations of R. kawakamii an R. retusum, only the cross of R. kawakamii (♂) with R. santapaui produced healthy seedlings. Of the remaining seven interspecific crosses only three showed significant embryo development in control pistils left to mature in situ. Similarities and differences in the breeding behaviour of R. kawakamii and R. retusum are discussed with reference to their taxonomic grouping within subsection Pseudovireya.


2016 ◽  
Vol 150 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Margret Scholz ◽  
Galina Pendinen

The pairing behaviour of the individual chromosome arms of Hordeum vulgare (Hv) with their homoeologous arms of H. bulbosum (Hb) at metaphase I of meiosis in tetraploid Hb × Hv hybrids and the frequencies of recombined Hv chromosome arms in selfed offspring were studied on differentially visualized chromosomes after fluorescent in situ hybridisation. The frequencies of paired Hv-Hb arms in the F2 and F3 hybrids were correlated with the frequencies of recombined Hv chromosomes in progenies. Self-generation of hybrids, the number of Hv and Hb chromosomes, and the number of recombined Hv chromosomes of the hybrids strongly influenced the Hv-Hb pairing frequency in meiosis. Within the offspring of F2 and F3 hybrids both Hv plants and hybrids were detected. In contrast, all progenies of the F4 hybrid were hybrids which exhibited centromere misdivisions. The highest frequencies of homoeologous pairing in hybrids and most recombinants were obtained for the barley chromosome 1HL. Recombinants for 4HL, 5HS, 6HS, and 7HS were rarely found. Meiotic pairing and recombinants involving chromosome 1HS were never observed. The results of this study demonstrate that fertile tetraploid interspecific hybrids with a high intergenomic pairing at meiosis are valuable basic material for introgression breeding in barley.


2021 ◽  
Author(s):  
Jiahong Tian ◽  
Runhua Fan ◽  
Zongxiang Wang ◽  
Jiahao Xin ◽  
Zhongyang Wang

Abstract Silver/polyaniline (Ag/PANI) composites were prepared by an in-situ synthesis method. Interestingly, the permittivity changed from positive to negative along with the formation of percolation network. The plasma oscillations of free electrons from the network made a dominant effect on the negative permittivity behavior. Further investigation based on equivalent circuit analysis revealed that the composites with negative permittivity presented inductive character. The epsilon-negative composites can be applied to electromagnetic shielding, absorbing and attenuation.


Euphytica ◽  
2014 ◽  
Vol 201 (2) ◽  
pp. 195-213 ◽  
Author(s):  
Shiyi Tang ◽  
Zhonghua Teng ◽  
Tengfei Zhai ◽  
Xiaomei Fang ◽  
Fang Liu ◽  
...  

2017 ◽  
Vol 130 (4) ◽  
pp. 795-806 ◽  
Author(s):  
Xiaomei Fang ◽  
Xueying Liu ◽  
Xiaoqin Wang ◽  
Wenwen Wang ◽  
Dexin Liu ◽  
...  

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