Embryo Culture and Embryo Rescue in Brassica

Somatic embryogenesis is the best demonstration of totipotency in higher plants in which somatic cell produce whole plant like zygotic embryo. It is also demonstrated that immature, weak, hybrid or sometimes inviable embryos can be saved through in vitro culture to prevents its degradation. It may help to cross the reproductive barriers when interspecific hybrids developed. Brasssica is an economically valuable oil yielding and vegetable crop and India is the largest producer of oil seed rape in the world. Various factors affect the embryo rescue in Brassica like growth stage of the embryos, types and composition of the rescue medium etc. The embryo regeneration potential can improve through the modification of culture conditions in both zygotic as well as somatic embryo. Except the embryo culture other parts like ovule, ovary culture can also be done to developed interspecific hybrids. This chapter is focused on the embryo rescue techniques in the genus Brassica and summarizes possible ways of improving the technique used.

Regenerasi Pepaya melalui Kultur In Vitro

<p>A study was conducted in the Indonesian Center for<br />Agricultural Biotechnology and Genetic Resources Research<br />and Development to optimize papaya regeneration systems<br />through in vitro culture. Four steps were done, i.e., callus<br />induction, callus regeneration, root formation, and acclimatization.<br />Explant materials used were immature embryos of<br />papaya cv. Burung. Immature papaya embryos were cultured<br />on different media. The best medium for embryogenic<br />callus development was ½ MS + 10 mg/l 2.4-D + 60% sucrose<br />+ 143 mg/l adenine sulphate + 50 mg/l myo inositol +<br />400 mg/l glutamine, while that for callus embryo regeneration<br />was MS + 0.5 mg/l GA3 + 0.1 mg/l kinetin + Morel and<br />Wetmore Vitamin. Using this medium, the average of shoot<br />formation was three shoots per explant of embriogenic<br />callus, and the percentage of regenerated callus was 80%.<br />The color of shoot derived from this treatment was green.<br />Eighty percent of plants formed a complete root development<br />using ½ MS + 0.5 mg/l paclobutrazol media. Media hull<br />of rice and compost was the best medium for papaya plant<br />acclimatization. The percentage of survival on that acclimatization<br />step was 65%.</p>

The Role of Drought Stress on Anther Culture of Wheat (Triticum aestivum L.)

Drought stress was found to pose a significant effect on anther culture of wheat, namely Barkat, Kanchan and Pavon-76. Regeneration potentials of these varieties were determined by estimating the percentage of anther response, embryo induction, embryo regeneration and production of green and albino plants. It was observed that out of five treatments such as T1 (1 hr), T2 (3 hr), T3 (5 hr), T4 (7 hr) and T5 (9 hr) only T2 showed highest percentage of embryo yield and green plantlets. The T1 and T3 also gave significantly better results compared to the control. All the genotypes produced embryos and green plantlets and of them Barkat showed best performance followed by Kanchan and Pavon 76. Genotypes, under this study, produced green plants in addition to albinos but T4 and T5 showed three - fourfold higher albino plant production in comparison to treatments. Key words: Anther culture, Drought stress, Haploids, Triticum aestivum D.O.I. 10.3329/ptcb.v20i1.5965 Plant Tissue Cult. & Biotech. 20(1): 55-61, 2010 (June)