Assessment of Genetic Divergence in White Finger Millet [Eleusine coracana (L.) Gaertn.] Genotypes for Yield and Yield Contributing Traits

The present investigation is carried out to study the genetic divergence among 55 finger millet genotypes for fourteen quantitative characters using Mahalanobis D2 statistics during kharif, 2020. D2 statistics indicated that the genotypes studied were genetically diverse. The 55 genotypes of finger millet were grouped into 6 clusters irrespective of geographical diversity, indicating no parallelism between geographic and genetic diversity. Clusters I had highest number of 50 genotypes and remaining all clusters had solitary. A wider genetic diversity was observed for the different traits studied among the genotypes as evidenced by the formation of six clusters. Out of fourteen quantitative traits studied grain yield per plant contributed majorly towards divergence with the value of 15.65% followed by productive tillers per plant contributes (12%), harvest index (10%) and other traits contribute minorly for divergence.

Comparison of Post-transcriptional Gene Silencing (PTGS) Strategies for Developing Transgenic Plants Resistant to Tomato Leaf Curl Virus (ToLCV)

Tomato (Solanum lycopersicum L.), an economically important crop is host to many whitefly transmitted geminiviruses including tomato leaf curl virus (ToLCV). Genetically engineering resistance of pathogen through Post-transcriptional gene silencing (PTGS/RNAi) is a powerful strategy that can provide alternative to existing methods of producing virus resistant plants. We cloned and characterized ToLCV-replicase (TRP) gene from a local Dharwad, Karnataka, India ToLCV isolate for development of transgenic tomato plants. Plant expression vectors carrying viral replicase (rep) gene in sense, antisense, ihp (intron spaced hairpin) and HUTR (inverted repeats of heterologous 3΄-untranslated region) were constructed. Transgenic tomato plants carrying rep gene in different strategies when challenged with whiteflies carrying ToLCV showed varied degrees of resistance. Such plants were confirmed through PCR, GUS, Dot blot, Southern blot and semiquantitative PCR analysis. High degree of resistance was observed in the construct carrying both sense and antisense strand interrupted by intron (ihp). Our results demonstrate that, transgenic plants with simultaneous expression of sense and antisense strands are more efficient in gene silencing of ToLCV than those expressing either sense or antisense strand alone.