Creation of clary sage cultivar using cell engineering methods. 1. Obtaining of plant-regenerants in callus culture in vitro

To increase the efficiency in agricultural plant breeding, including clary sage – one of the main essential oil crops grown in Russia, it is necessary to use biotechnological methods. One of these techniques is based on the induction of somaclonal variability in the callus tissue culture. To develop it, it is necessary to optimize the conditions for obtaining plant-regenerants in vitro and their analysis. The aim of this work was to study the features of morphogenesis and regeneration of plants from callus cultures to develop cell technologies for creating an initial breeding material based on somaclonal variability in Salvia sclarea L. In the course of the research, we found that the optimal explants for obtaining morphogenic callus, from which shoots were regenerated, were segments of buds and stems with a node (isolated from seedlings in vitro). Cytological analysis of callus cultures revealed two types of morphogenesis – organogenesis (gemmogenesis) and somatic embryogenesis. The features of the morphogenic callus formation of six sage cultivars and samples during the long-term cultivation were studied. The maximum frequency of morphogenesis was noted in the 2nd passage (from 32.4 to 85.2 %, depending on the genotype). Then, to the 8–10th passage, this indicator decreased to 0.0–3.9 %.‘S-785’ and ‘Taigan’ cultivars showed the highest morphogenesis frequency (81.5–85.2 %) and duration of callus regeneration potential (up to the 10th passage). The analysis of callus cultures of six donor plants of ‘S-785’ cultivar helped us to reveal their heterogeneity in morphogenesis induction ability. The maximum frequency of morphogenic callus formation (76.3–91.5 % in the 2nd passage) and the duration of the morphogenic potential preservation (up to the 12th passage) were observed in plants No. 3 and 9, whereas in No. 2, regeneration with a frequency of 3.6–9.7 % was observed only during three passages. Analysis of plants obtained from calli showed their variability in morphology – up to 12.5 % of the samples had deviations compared to the initial cultivar ‘S-785’ in leaf shape, inflorescence structure, flower color, etc. Somaclonal changes in morphological and economically useful traits revealed in regenerants indicate that they are promising for use in sage breeding.

A review on corn breeding for insect pest resistance

Significant yield reduction and effect on almost every aspect of the plants by insect pests have been a mega problem in agricultural crops. Scientist tackle with many challenges to develop highly efficient techniques either through conventional breeding or modern genetic engineering to understand the mechanism of resistance and its application for benefit of human kind. Antibiosis, antixenosis and tolerance are the resistance mechanisms which have been developed for successful control of economically important insect pests in corn. Plant morphology and allelochemicals, induced resistance, callus tissue culture and genetic transformation were used as major tools to advance resistance by corn breeders. Insect pest resistant corn has been attributed for social, economical as well as environmental benefits. However, outcome of these achievements are not reflected due to low use of insect resistant corn by farmers in many developing countries of the world.

Callus Induction and Plant Regeneration in Rauvolfia Serpentina (L.) Benth Ex. Kurz.

Rauvolfia serpentina (L.) ex. Kurz is an important medicinal plant. Callus induction and regeneration was studied from stem explant of in-vitro grown plant of Rauvolfia serpentina(L.) Benth. ex Kurz (Apocynaceae) on Murashige Skoog (1962) medium supplemented with 1mg/l 2,4-Dichlorophenocy acetic acid (2,4-D) and 1mg/l Kinetin (Kn). Vigorous growth of callus occurs after 4 weeks of culture. Callus was sub-cultured on Murashige and Skoog (MS) medium supplemented with different concentration of 2, 4-D (0.5-3.0 mg/l) and 10% coconut milk. Regeneration of plantlets occurred on MS medium containing 3 mg/1 of 2, 4-D and 10% coconut milk. These plantlets were rooted on MS medium supplemented with 1 mg/l IAA .The regenerated plantlets were able to grow on soil after short period ofacclimatization. Key words: Explant; In-vitro culture; MS medium; 2, 4 Dichlorophenoxy acetic acid; Kinetin; Callus; Tissue culture; Coconut milk. Journal of Natural History Museum Vol. 24, 2009 Page: 82-88

The mitochondrial genome organization of a maize fertile cmsT revertant line is generated through recombination between two sets of repeats.

The mitochondrial genome (mtDNA) organization from a fertile revertant line (V3) derived from the maize cytoplasmic male sterile type T (cmsT) callus tissue culture has been determined. We report that the sequence complexity can be mapped on to a circular "master chromosome" of 705 kb which includes a duplication of 165 kb of DNA when compared to its male sterile progenitor. Associated with this event is also a 0.423-kb deletion, which removed the cmsT-associated urf13 gene. As found for the maize normal type (N) and cmsT mitochondrial genomes, the V3 master chromosome also exists as a multipartite structure generated by recombination through repeated sequences.

Cytogenetics of tissue culture regenerated hybrids of Triticum tauschii × Secale cereale

Immature inflorescences of Triticum tauschii (Coss.) Schmal. × Secale cereale L. cv. 'Puma' hybrids were induced to callus on Kao's medium supplemented with 5 mg/L 2-4-dichlorophenoxyacetic acid (2.4-D). Plantlets with diploid and tetraploid chromosome numbers were subsequently regenerated from the callus. Chromosome pairing in the diploid regenerants and tetraploid amphiploids was incomplete and the plants were sterile.Key words: Triticum, Secale, chromosome pairing, callus, tissue culture.