Transgenic technology serves to introduce gene sequences for expression of a desired trait. Production of transgenic plants is reported in many crops, but commercialization is limited to a few selected crops, such as cotton (Gossypium hirsutum L.), corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and canola (Brassica napus L. and B. rapa L.). This paper presents the sequential processes of transgenic event design, event selection, and “cleaning up” genetic background for forward breeding programs. Expression of the foreign gene cannot be viewed in isolation and is more complex than has been assumed because of the interaction of transgene with native genes. Variations among clones and within the progeny are observed, and hence all the clones are taken into account for evaluation. Plant breeding must be involved to move transgenes from transformable but agronomically unacceptable genotypes into elite breeding lines with two backcrosses. Production of transgenic plants in large numbers is difficult and laborious and requires large investments. It is worthwhile investing in parallel efforts to incorporate the transgene into improved plant material to satisfy commercial interests.

Flax ( Linum usitatissimum ) is a cool season crop commercially cultivated for seed oil and stem fibre production. A comprehensive characterization of the heat shock factor ( HSF ) candidate genes in flax can accelerate genetic improvement and adaptive breeding for high temperature stress tolerance. We report the genome-wide identification of 34 putative HSF genes from the flax genome, which we mapped on 14 of the 15 chromosomes. Through comparative homology analysis, we classified these genes into three broad groups, and sub-groups. The arrangement of HSF-specific protein motifs, DNA-binding domain (DBD) and hydrophobic heptad repeat (HR-A/B), and exon-intron boundaries substantiated the phylogenetic separation of these genes. Orthologous relationships and evolutionary analysis revealed that the co-evolution of the LusHSF genes was due to recent genome duplication events. Digital and RT-qPCR analyses provided significant evidence of the differential expression of the LusHSF genes in various tissues, at various developmental stages, and in response to high-temperature stress. The co-localization of diverse cis-acting elements in the promoters of the LusHSF genes further emphasized their regulatory roles in the abiotic stress response. We further confirmed DNA-binding sites on the LusHSF proteins and designed guide RNA sequences for gene editing with minimal off-target effects. These results will hasten functional investigations of LusHSFs or assist in devising genome engineering strategies to develop high-temperature stress tolerant flax cultivars.

Kanti M., Anjani K., Usha Kiran B., Vivekananda K. (2015): Agro-morphological and molecular diversity in castor (Ricinus communis L.) germplasm collected from Andaman and Nicobar Islands, India. Czech J. Genet. Plant Breed., 51: 96-109.Castor (Ricinus communis L.) is an industrial oilseed crop grown worldwide. Its oil with more than 80% ricinoleic acid makes it a chief raw material for numerous industrial applications and biofuel production. Castor grows in a wild form across India including Andaman & Nicobar Islands, which are geographically quite isolated from mainland India. Thirty-three accessions growing in isolation in these Islands were used in the present study. Genetic diversity among these accessions was assessed using 18 agro-morphological traits and 29 EST-SSR markers. High agro-morphological and molecular variability was observed among these accessions. Both agro-morphological traits and EST-SSR markers effectively discriminated the accessions. However, EST-SSRs separated the accessions into more groups than did agro-morphological data, implying high efficiency and resolution of EST-SSR markers in genetic analysis of castor germplasm from Andaman & Nicobar. The diverse accessions identified in the present investigation would serve as genetically diverse sources in castor breeding programmes.

Tossa jute (Corchorus olitorius L.) is an important lingo-cellulosic bast fibre-crop. It provides biodegradable and environment friendly fibre next to cotton, in terms of usage, global consumption, production, and availability. Narrow genetic diversity of the crop is the major hurdle, which is a demand at priority for any crop improvement programme. In the current investigation 138 jute genotypes of C. olitorius were characterized with ten jute specific SSR markers. A total of 23 alleles were amplified with an average of 2.3 alleles per locus and the PIC value ranged from 0.13 to 0.76 with an average of 0.455. The un-weighted pair-group method with arithmetic average cluster analysis of the 138 jute genotypes depicted a dendrogram using DARWIN, which divided the genetic resource into three major clusters. The study indicated the utility of SSR primers for providing useful and high levels of polymorphism for individual plant genotypes even with a narrow genetic base. Based on cluster analysis the most divergent genotypes identified were OIJ 167 (from Indonesia), OIM 058 and OIM 059 (India), however based on the agronomic traits as maximum plant height, basal diameter and fibre weight they were OIJ 245, OIJ (153 and 161) and OIJ 040, respectively.

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