Optimum age of siliques for rescue of hybrid embryos from crosses between Brassica oleracea, B. rapa and B. carinata

2004 ◽  
Vol 84 (4) ◽  
pp. 965-969 ◽  
Author(s):  
M. H. Rahman

Interspecific hybrids were produced from crosses involving Brassica rapa var. Yellow Sarson (AA), Canadian B. rapa (AA) cultivars, B. oleracea var. alboglabra (CC), B. oleracea var. italica (CC), rapidcycling B. oleracea (CC) and B. carinata (BBCC) to introgress the yellow seed color or self-incompatibility genes into B. napus. Embryo rescue technique was employed for this purpose. In interspecific crosses where a CC genome species was used as the female parent, a significantly lower number of ovules were fertilized compared to the crosses where the BBCC genome species was female. Embryo growth and development were slower in the crosses where the CC genome species was female than in the crosses where BBCC genome species was female. The efficiency of the embryo rescue technique from 16 to 40 d after pollination (DAP) with 4-d intervals was investigated in the crosses using CC genome species as female. The highest numbers of embryos were rescued between 20 and 28 DAP depending upon the specific cross undertaken. However, the survival rate of the embryos rescued at 20 DAP was very low compared to the embryos rescued at 24 and 28 DAP. The survival rate of the embryos rescued at 32 DAP was generally high, but the number of embryos rescued at this stage was significantly lower than at 24 and 28 DAP. No embryos were obtained at 16 DAP or at 40 DAP. Thus, using the CC genome species as female parent, the maximum efficiency of the embryo rescue technique was achieved when embryos were rescued between 24 and 28 DAP. In the case of crosses using the BBCC genome species as female, rescue of hybrid embryos was successful at 18 and 22 DAP. Key words: Brassica, interspecific cross, embryo rescue, embryo development

2006 ◽  
Vol 41 (6) ◽  
pp. 969-973 ◽  
Author(s):  
Adriana Cibele de Mesquita Dantas ◽  
José Itamar Boneti ◽  
Rubens Onofre Nodari ◽  
Miguel Pedro Guerra

The objetive of this work was to rescue immature embryos of apple rootstocks Malus prunifolia (Marubakaido) and Malus pumila (M9) after 40-60 days of pollination and to put them into MS culture media supplemented with agar (6 g L-1) and casein hydrolysate (500 mg L-1). Embryos originated from interspecific crosses and open pollination showed differences in the in vitro responses, depending on the female parent, the developmental stage of the embryo, and the culture medium composition. Embryos of the M. pumila rootstock, rescued within 40 days after pollination and put in culture medium supplemented with indolacetic acid (IAA), gibberellic acid (GA3), kinetin and maltose, resulted in a normal development of plantlets. However, embryos originating from hand-pollination, cultivated in medium supplemented with 14 µM IAA, 5 µM kinetin and 1.5 µM Ga3 (MS1), mainly those of M. prunifolia x M. pumila, showed a high percentage of rusted embryos (96.2%). Embryos from open pollination of M. prunifolia and M. pumila formed calluses. It was possible to identify the influence of the female parent by the enhanced development of M. pumila shoots derived from open or hand-pollination. The crossing of responsive species and the use of the technique of embryo culture provided a rapid and uniform germination and, consequently, the development of fully normal seedlings.


2011 ◽  
Vol 59 (4) ◽  
pp. 382 ◽  
Author(s):  
Agnieszka Bagniewska-Zadworna ◽  
Maciej Zenkteler ◽  
Elzbieta Zenkteler ◽  
Maria K. Wojciechowicz ◽  
Abdelali Barakat ◽  
...  

Embryos and plants from the crosses Salix viminalis L. as the female parent and Populus alba L., P. violascens Dode or P. tremula L. as the male parent were obtained by in vitro embryo rescue technique. F1 intergeneric progeny were obtained by overcoming post-zygotic barriers caused by the deficiency of endosperm as nutritive tissue during the first stage of embryo development. Ovules containing immature heart-stage embryos as well as early cotyledonary embryos were isolated and rescued in modified 1/2 MS medium supplemented with 3% sucrose to ensure maturity. Seedlings were cultured under in vitro conditions in 1/2 MS medium that contained 0.2 mg l–1 naphtaleneacetic acid and plantlets after rooting were transferred first into pots and subsequently to the experimental field in the Botanical Garden in Poznań, Poland. After 2 years, the putative hybrid nature of the plants was checked by analysing morphological characters and molecular markers. Scanning electron microscopy, flow cytometry and random amplification of polymorphic DNA screening of individuals confirmed the hybrid nature of the S. viminalis × P. alba and S. viminalis × P. violascens progeny and of 25% of the analysed plants from the cross S. viminalis × P. tremula. This study showed the feasibility of overcoming pre- and post-fertilisation barriers to achieve intergeneric hybrids between species from two genera of Salicaceae. The in vitro system to produce hybrids with characters of both parents could be of great importance for increasing biomass production. This study also opens new opportunities to improve other traits in trees, such as resistance to pathogens inherited from one parent.


2019 ◽  
Vol 55 (No. 1) ◽  
pp. 28-34
Author(s):  
Yi-Qian Ju ◽  
Xing Hu ◽  
Yao Jiao ◽  
Yuan-Jun Ye ◽  
Ming Cai ◽  
...  

Interspecific crosses play an important role in gene introgression, plant improvement and speciation. However, poor fertility of F<sub>1</sub> generation was commonly found, which hampered backcrossing and ideal progeny generation. To explore useful materials for further breeding programs, sterile hybrids (DD1, FD1, ZD3) from different cross combinations of Lagerstroemia indica and L. speciosa and the fertile hybrid (ZD6) were selected. The results showed that pollen grains of sterile hybrids had no germination ability while ZD6 showed 25.90% pollen germination rate. The morphology of stigmas and their papilla cells showed no apparent difference. Normal pollen tubes could be detected in ovaries of ZD6 and ZD3 24 h after pollination. However, the enlarged ovaries of ZD3 began to abscise at 72 h after pollination, which suggested that the barriers occurred during post-fertilization phases. As a consequence, ZD6 can be used as either male or female parent for further Lagerstroemia breeding programs, while the sterile hybrids may be used as female parent through embryo rescue culture.  


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1040D-1041 ◽  
Author(s):  
Mi-Young Chung ◽  
Jae-Dong Chung ◽  
Jaap Van Tuyl ◽  
Ki-Byung Lim

Intergenomic F1 hybrids between L. auratum and L. henryi were made and backcrossed to Oriental hybrids to produce BC1 progenies. The F1 intergenomic hybrids produced a relevant frequency of 2n-gamete and fertile pollen. Analyses of pollen size, viability, and germination ability were checked under microscopic observation. GISH analysis confirmed that F1 intergenomic hybrids possess a set of chromosomes from both parents and showed an intermediate morphological phenotype. Twenty BC1 plants were generated by in vitro embryo rescue technique, and analyzed for genome composition by GISH. All plants were triploid, showing 12 from female parent (2× Oriental) and 24 from male (2× F1 hybrid). Based on the GISH analyses, 19 BC1 plants were derived from FDR 2n-gamete and only one plant was derived from IMR 2n-gamete of F1 hybrid. The genome composition of 19 BC1 plants from FDR 2n-gamete possess 12 Orientals + 12 L. auratum + 12 L. henryi chromosomes with some extent of homoeologous recombination between L. auratum and L. henryi. However, one plant from IMR 2n-gamete origin contains an odd number of parental chromosomes from F1 hybrid, showing 12 Oriental + 14 L. auratum + 10 L. henryi chromosomes. In this case, two L. auratum chromosomes recombinant with L. henryi chromosome segments were added and L. henryi counterpart chromosomes were deleted, respectively.


1999 ◽  
Vol 75 (5) ◽  
pp. 833-836 ◽  
Author(s):  
Louis Zsuffa ◽  
Dolly Lin ◽  
Peggy Payne

New evidence is described on one way crossing barriers between Aigeiros and Tacamahaca species, gained in experimental full-sib crosses. The technique of crosses and embryo rescue are described. In some crosses of questionable result, the embryo rescue was successful. The possible genetic mechanisms underlying the crossing barriers are discussed. Key words: Populus, hydridization, embryo rescue, crossing barriers


2000 ◽  
Vol 125 (4) ◽  
pp. 489-497 ◽  
Author(s):  
Veli Erdogan ◽  
Shawn A. Mehlenbacher

Eight Corylus L. (hazelnut) species were intercrossed in all possible combinations to reveal genetic relationships. Pollinations were made on either individually bagged branches or trees covered entirely with polyethylene using mixtures of pollen of five genotypes to minimize low cluster set due to single incompatible combinations. Percent cluster set, seed germination, and hybrid seedling survival were determined. Hybridity of seedlings was verified by inspection of morphological traits. Based on percent cluster set, seed germination, and hybrid seedling survival along with observed morphological similarities, Corylus species were placed in three groups: 1) the tree hazels C. colurna L. (turkish tree hazel) and C. chinensis Franchet (chinese tree hazel), 2) the bristle-husked shrub species C. cornuta Marshall (beaked hazel), C. californica (A.DC.) Rose (california hazel), and C. sieboldiana Blume (manchurian hazel), and 3) the leafy-husked shrub species C. avellana L. (european hazel), C. americana Marshall (american hazel), C. heterophylla Fischer (siberian hazel), and C. heterophylla Fischer var. sutchuensis Franchet (sichuan hazel). The two tree hazel species crossed with each other readily, as did the three bristle-husked shrub species. The frequency of blanks was low (<20%) for crosses of the tree hazels, and <50% for interspecific crosses within the group of bristle-husked species. The leafy-husked shrub species could be crossed with each other in all directions, although cluster set on C. heterophylla was low. For crosses of species belonging to different groups, set was generally low and the frequency of blanks high. Nevertheless, a few hybrid seedlings were obtained from several combinations. When used as the female parent, C. californica set nuts when crossed with all other species, indicating possible value as a bridge species. Crosses involving C. avellana were more successful when it was the pollen parent. In crosses with C. avellana pollen, cluster set on C. chinensis was better than on C. colurna and the frequency of blanks was much lower, indicating that it might be easier to transfer nonsuckering growth habit from C. chinensis than from C. colurna. Reciprocal differences in the success of crosses was observed. The following crosses were successful C. californica × C. avellana, C. chinensis × C. avellana, C americana × C. heterophylla, C. cornuta × C heterophylla, C. californica × C. colurna, and C. americana × C. sieboldiana, but the reciprocals were not.


Author(s):  
Monika M. Lulsdorf ◽  
Alison Ferrie ◽  
Susan M. H. Slater ◽  
Hai Ying Yuan

HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Natalia R. Dolce ◽  
Luis A. Mroginski ◽  
Hebe Y. Rey

An in vitro culture protocol was developed that increased the germination percentage and decreased the lag time to germination for Ilex dumosa R. pyrenes as a tool for replacing the laborious task of embryo rescue technique. This method involves transversely cutting surface-sterilized pyrenes with a scalpel blade, then placing the micropylar one-third end with the rudimentary embryo (≈0.25 mm long) on solidified (agar 0.65%) quarter-strength salts and vitamins of Murashige and Skoog, 1962 medium with 3% sucrose, and incubating in a growth room at 27 ± 2 °C with a 14-h photoperiod (116 μmol·m−2·s−1). Most of the cut pyrenes (greater than 50%) germinated within the first month after inoculation and achieved maximum germination (≈70%) in 2 months compared with whole pyrenes, which began to germinate 3 months after sowing and required more than 8 months for maximum germination (37%). Moreover, the germination percentage of cut pyrenes was significantly higher than the germination of isolated embryos (34%). Thus, the cut pyrenes culture is a simpler and more effective technique than embryo rescue. Easily, on average, a trained operator is able to culture ≈1000 cut pyrenes per day instead of ≈100 isolated embryos.


Genome ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 27-35 ◽  
Author(s):  
K. N. Watanabe ◽  
M. Orrillo ◽  
S. Vega ◽  
J. P. T. Valkonen ◽  
E. Pehu ◽  
...  

The first direct sexual hybrids between diploid nontuber-bearing species and diploid potato breeding lines are reported here. Three nontuberous species of Solanum, S. brevidens, S. etuberosum, and S. fernandezianum, were used for sexual crosses, achieved by a combination of rescue pollinations and embryo rescue. Initial hybrid selection was made using an embryo spot marker, followed by the evaluation of morphological and reproductive traits. Putative hybrids were first tested for resistance to potato leaf roll virus derived from the wild species, and then were tested with molecular markers using species-specific DNA probes. Finally, the tuberization of several 2x hybrids was tested for actual potato germplasm enhancement. These hybrids are unique in terms of their potential to enhance recombination between chromosomes of wild species and those of cultivated potatoes in germplasm utilization, and to exploit the genetic nature of tuber formation. The finding that nontuber-bearing Solanum spp. can be directly crossed with tuber-bearing species also has important implications for the regulatory aspects of the use of genetically modified organisms.Key words: nontuber-bearing Solanum, potato germplasm enhancement, interspecific crosses, chromosome manipulation, inter-EBN crosses, diploid.


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