Hybrid Embryo Rescue in Crop Improvement

As plant biotechnology is an application of cell engineering by which the plant cell genome is manipulated to improve agricultural productivity, leading to increases in production, many fundamental questions related to crop improvement arise, such as (i) how to propagate a great number of plants in a small space and within a shorter period of time; (ii) how to control the reversion to juvenility in forest species; (iii) how to decrease the time required to release new varieties to plant producers; (iv) how to control pests without causing environmental pollution; (v) how to regenerate intact transgenic plants after DNA insertion into protoplasts; (vi) how to transfer genetic characters between incompatible plant species; (vii) how to obtain somaclones resistant to adverse conditions; (viii) identification of the molecular mechanisms governing the processes of plant cell morphogenesis and how to control them to obtain better agricultural performance. Many of these questions are being studied in our laboratory and the results are discussed here.Key words: plant biotechnology, micropropagation, transgenic plants, somaclonal variation, hybrid embryo rescue, plant tissue culture.

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Embryo Rescue Culture Medium for Improved Synthesis of 4x Wheat × Rye Hybrids

Australian Journal of Botany ◽

10.1071/bt9940493 ◽

1994 ◽

Vol 42 (4) ◽

pp. 493

Author(s):

CH Balatero ◽

NL Darvey

Keyword(s):

Embryo Rescue ◽

Favourable Effect ◽

Embryo Formation ◽

Step Procedure ◽

Hybrid Embryo ◽

One Step ◽

Well Differentiated ◽

Semi Solid ◽

Optimum Recovery

The cross-incompatibility barrier between 4x wheat and rye has limited the genetic base for triticale breeding. Experiments designed to improve the synthesis of wheat-rye amphihaploids were conducted. The effects of 2,4-D on crossability and 3x hybrid embryo differentiation, and the influence of one-step and two-step media on the culture of immature 3x embryos in vitro, were investigated. Application of 10 mg L-1 2,4-D slightly improved seed set but significantly reduced the frequency of normal embryos. In contrast to the reported favourable effect of 2,4-D on haploid embryo formation in wheat × maize crosses, the application of 2,4-D in the present study offers no real advantage on amphihaploid embryo formation from 4x wheat × rye crosses. For small and immature wheat-rye hybrid (3x) embryos, optimum recovery in vitro was obtained via a two-step procedure consisting of a semi-solid MN medium followed by MS medium supplemented with IAA (1 mg L-1) and BAP (1 mg L-1). For bigger and well-differentiated embryos, the use of a one-step Gamborg's B5 medium was sufficient.

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Wide Hybridization and Embryo-Rescue for Crop Improvement in Solanum

Agrotechnology ◽

10.4172/2168-9881.s11-004 ◽

2013 ◽

Vol 01 (S11) ◽

Cited By ~ 2

Author(s):

V.K Khanna

Keyword(s):

Embryo Rescue ◽

Crop Improvement ◽

Wide Hybridization

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Interspecific hybridization of Medicago sativa L. and M. rupestris M. B. using ovule–embryo culture

Canadian Journal of Genetics and Cytology ◽

10.1139/g85-035 ◽

1985 ◽

Vol 27 (2) ◽

pp. 238-245 ◽

Cited By ~ 27

Author(s):

T. J. McCoy

Keyword(s):

Medicago Sativa ◽

Embryo Culture ◽

Interspecific Hybrid ◽

Interspecific Hybrids ◽

Embryo Rescue ◽

Culture Method ◽

Hybrid Plants ◽

Successful Recovery ◽

Hybrid Embryo ◽

Medicago Sativa L

An ovule–embryo culture method was used to produce the first interspecific hybrids between alfalfa (Medicago sativa L.) and Medicago rupestris M. B. Culture of fertilized ovules from the cross diploid (2n = 2x = 16) M. sativa (jpjp) × diploid (2n = 2x = 16) M. rupestris began 14 days after pollination. After 5 days in culture, the interspecific hybrid embryo was removed and transferred to fresh medium, where development into a plant occurred. Forty-six M. sativa – M. rupestris F1 hybrids have been recovered using this technique. All but one of the 46 F1 hybrids were diploid (2n = 2x = 16); the only exception was tetraploid (2n = 4x = 32). The most frequent meiotic configurations observed in the F1 hybrid plants were eight bivalents or seven bivalents and two univalents, indicating significant homology between M. sativa and M. rupestris genomes. However, pollen stainability (0–12%) and pollen germination (0–6%) were extremely low. Similar to the production of the F1, no first backcross (BC1) plants were obtained from seed; however, the ovule–embryo culture method was found to be a very effective method for recovering BC1 plants and hundreds of BC1 plants have been produced. The BC1 plants from crossing the F1 with diploid M. sativa were predominantly diploid. Medicago rupestris can now be considered a potential germplasm source for alfalfa improvement. The ovule–embryo culture method represents the first successful recovery of Medicago interspecific hybrids via some form of embryo rescue. Importantly, it appears this technique can be applied to other interspecific hybrid combinations in the Medicago genus.Key words: Medicago, alfalfa, embryo culture, interspecific hybrid.

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Culture of Embryo with a Segment of Ovary Improved Germination and Crossability of Distant Hybrids in Indica Rice

Scientific World ◽

10.3126/sw.v5i5.2655 ◽

1970 ◽

Vol 5 (5) ◽

pp. 46-50

Author(s):

Bindeshwar Prasad Sah ◽

Raj Kumar Niroula ◽

Hari Prasad Bimb

Keyword(s):

Wild Species ◽

Indica Rice ◽

Embryo Rescue ◽

Continuous Light ◽

Male Sterile ◽

Cultivated Rice ◽

Distant Hybridization ◽

Hybrid Plants ◽

Hybrid Embryo

Distant hybridization in the genus Oryza is realized as an efficient Biotechnological tool for plant breeding work to introgress useful gene/s from diverse array of wild relatives into cultivated rice. This study was carried out to improve the germination frequency of hybrid embryo to enhance the crossability between O. sativa sub spp. indica and wild species. Three cultivars of indica rice viz. IR 64, Radha 4 and IR 69618 - CMS A line (cytoplasmic male sterile A line) were pollinated with the pollen of O. latifolia, O. minuta and O. officinalis. Hybrid caryopsis containing embryos were rescued at tenth day of pollination. In vitro germination frequency of rescued embryos were compared by culturing embryo alone and embryo with a bit of ovary during 2005-06 at Biotechnology Unit, Khumaltar, Lalitpur, Nepal. Culture was maintained at 25±1°C under dark until germination and there after continuous light. In majority of the cross combinations, the germination frequencies were found to be higher when embryo excised and cultured with small portion of ovary. This technique yielded up to 100 per cent germination which were later employed to study the crossability between species. Depending upon the cultivars of O. sativa, the frequencies of crossability varied from 0.53 to 3.08 per cent with highest for Radha 4/O. minuta. A total of 38 hybrid plants were successfully produced from 88 cultured embryos isolated from 2644 pollinated florets. Inclusion of a bit of ovary along with embryo in in vitro culture was found to be an effective method not only to improve the germination frequency of hybrid embryo, but also to increase the crossability between cultivars of cultivated rice and their distant relatives. Key words: Embryo rescue; Interspecific hybrid; Oryza sativa; Wild species; O. latifolia; O. minuta; O. officinalis. DOI: 10.3126/sw.v5i5.2655 Scientific World, Vol. 5, No. 5, July 2007 46-50

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Hybrid embryo rescue

Plant Tissue Culture Manual ◽

10.1007/978-94-009-0103-2_46 ◽

1993 ◽

pp. 801-808 ◽

Cited By ~ 1

Author(s):

Abha Agnihotri

Keyword(s):

Embryo Rescue ◽

Hybrid Embryo

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Seed and Embryo Growth in Pod Cultures of Phaseolus vulgaris and P. vulgaris × P. acutifolius

HortScience ◽

10.21273/hortsci.25.10.1288 ◽

1990 ◽

Vol 25 (10) ◽

pp. 1288-1291 ◽

Cited By ~ 5

Author(s):

Ana Maria Sabja ◽

David W.S. Mok ◽

Machteld C. Mok

Keyword(s):

Interspecific Hybrid ◽

Embryo Rescue ◽

Precocious Germination ◽

Developmental Arrest ◽

Hybrid Embryo ◽

Murashige Skoog ◽

Cotyledonary Stage ◽

Pod Culture ◽

Culture Procedure

Interspecific hybrid embryos resulting from crosses between Phaseolus species generally fail to reach maturity, and embryo rescue techniques are required to recover plants. To determine if ovary (pod) culture could permit interspecific hybrid embryo development, pods of P. vulgaris L. × P. acutifolius A. Gray and P. vulgaris L. (control) were cultured upright, supported by glasswool, in modified Murashige-Skoog liquid medium. The weight of seeds and length of embryos in P. vulgaris pods increased significantly during culture. However, usually only one or occasionally two seeds located at the middle positions of the pods developed to maturity. The same pod culture procedure promoted precocious germination of early cotyledonary-stage P. vulgaris × P. acutifolius embryos without further maturation of the embryos. These findings confirm that developmental arrest of the interspecific hybrid embryos in vivo is due to intrinsic deficiencies.

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Advances in Agricultural Biotechnology

Nepal Journal of Biotechnology ◽

10.3126/njb.v9i1.38643 ◽

2021 ◽

Vol 9 (1) ◽

pp. 85-92

Author(s):

Mamata K.C. ◽

Anuj Lamichhane

Keyword(s):

Crop Production ◽

Crop Yields ◽

Agricultural Biotechnology ◽

Embryo Rescue ◽

Crop Improvement ◽

Genetically Modified Crops ◽

Yield Potential ◽

Genome Doubling ◽

Transgenic Organisms ◽

Biotechnological Approach

Agricultural biotechnology is becoming the major sector in crop improvement through the use of scientific techniques for the modification of genes conferring resistance to biotic, abiotic stress and improving the quality of crops. With the evolvement from Mendelian genetics to molecular biotechnology, there have been several developments in the field of crop improvement. Recent biotechnological advances have aimed towards removing the physiological constraints of the crops and increasing crop yield potential. With the use of different tools of agricultural biotechnologies like genetic engineering, tissue culture, embryo rescue, somatic hybridization, molecular marker-assisted selection, genome doubling, and omics technologies, various transgenic crops have been developed over the decades and have been approved for commercialization. This development and adoption of transgenic technology have been shown to increase crop yields, reduce CO2 emission, reduce pesticide and insecticide use and decrease the costs of crop production. Even though the biotechnological approach and transgenic organisms have immense potential to contribute to the world’s food security, several concerns of genetically modified crops being a threat to the environment and human health have developed. This review will address applications and concerns of biotechnology in crop improvement considering health hazards and ecological risks.

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