Ectopic expression of Atleafy in Brassica juncea cv. Geeta for early flowering.

High temperature stress during pod filling severely affects the yield of Brassica juncea. Early flowering can evade the terminal heat stress and result in early maturity of the crop. In this study, a regeneration and transformation protocol has been standardized for B. juncea cv. Geeta. Hypocotyl from 5-day-old seedlings were used as explants. Of the various combinations of auxins and cytokinins tried along with Murashige and Skoog's (Physiol Plant 15:473-497, 1962) medium, MS + IAA (0.2 mg/l) + BA (3 mg/l) proved best for shoot regeneration with 89.9 % regeneration efficiency. To induce early flowering Leafy gene from Arabidopsis thaliana was transformed using Agrobacterium mediated transformation method. After 12 weeks transgenic plants showed flowering in vitro whereas their untransformed counterpart did not flower even after 16 weeks. The maximum transformation frequency was 4 %.

ISSR markers for gender identification and genetic diagnosis of Hippophae rhamnoides ssp. turkestanica growing at high altitudes in Ladakh region (Jammu and Kashmir).

Hippophae rhamnoides L. ssp. turkestanica (Elaeagnaceae) is a predominantly dioecious and wind-pollinated medicinal plant species. The mature fruits of the species possess antioxidative, anti-inflammatory, antimicrobial, anticancerous, and antistimulatory properties that are believed to improve the immune system. The identification of male and female plants in H. rhamnoides ssp. turkestanica is quite difficult until flowering which usually takes 3-4 years or more. A sex-linked marker can be helpful in establishing the orchards through identification of genders at an early stage of development. Therefore, we studied the genetic diversity of populations in Ladakh with the aim to identify a gender-specific marker using ISSR markers. Fifty-eight ISSR primers were used to characterize the genome of H. rhamnoides ssp. turkestanica, of which eight primers generated 12 sex-specific fragments specific to one or more populations. The ISSR primer (P-45) produced a fragment which faithfully segregates all the males from the female plants across all the three valleys surveyed. This male-specific locus was converted into a SCAR. Forward and reverse primers designed from this fragment amplified a 750-bp sequence in males only, thus specifying it as an informative male-specific sex-linked marker. This SCAR marker was further validated for its capability to differentiate gender on an additional collection of plants, representing three geographically isolated valleys (Nubra, Suru, and Indus) from Ladakh region of India. The results confirmed sex-linked specificity of the marker suggesting that this conserved sequence at the Y chromosome is well preserved through the populations in Ladakh region. At present, there are no reliable markers which can differentiate male from female plants across all the three valleys of Ladakh region at an early stage of plant development. It is therefore envisaged that the developed SCAR marker shall provide a reliable molecular tool for early identification of the sex in this commercial crop. The genetic diversity of populations as surveyed by ISSR primers revealed 85.71 % polymorphism at the population level. The dendrogram obtained divided the genotypes into three different clusters, and the distribution of male and female genotypes in all the clusters was random. The Nei's genetic similarity index was in the range of 0.63-0.96.

Authentication of medicinal plants by DNA markers.

Medicinal plants have been used worldwide for centuries to maintain health and to treat diseases, more so chronic diseases. However, adulteration and use of spurious materials as substitutes have become a major concern for users and industry for reasons of safety and efficacy. Therefore, authentication of medicinal plants is of utmost importance. Morphological, anatomical, chemical and DNA markers solve the problem by differentiating the genuine material from the adulterants, substitutes and spurious drugs. DNA markers use nucleotide sequences to identify species; it takes preference over the other two markers being not age dependent, tissue specific and having a higher discriminating power. Therefore, characterization of plants with such markers is an ideal approach for identification of medicinal plant species and populations/varieties of the same species. Availability of certified taxonomic specimens in herbaria is certainly required for unambiguous confirmation through final visual comparison and analysis.

Genetic diversity and chemical profiling of different populations of Convolvulus pluricaulis (convolvulaceae): an important herb of ayurvedic medicine.

Convolvulus pluricaulis Choisy, commonly known as "Shankhpushpi", is an ayurvedic medicinal plant recommended as a brain tonic to promote intellect and memory, eliminate nervous disorders and to treat hypertension. Because of increasing demand of the drug, this plant species has been over-exploited. As a consequence, many unrelated plants are being sold by the crude drug dealers in India in the name of "Shankhpushpi". Information on its existing gene pool is currently lacking. We developed molecular (Random Amplification of Polymorphic DNA) and chemical (high performance liquid chromatography) markers that could distinguish the genuine plant species from its adulterants. Molecular characterization confirmed higher genetic variation at inter-zonal level as compared to intra-zonal populations. A total of 37 reproducible amplicons were generated of which 22 were polymorphic. The number of amplicons was in the range of 6-11 and genetic distance for the studied primers ranged from 0.07 to 0.34. Fifty nine per cent polymorphism was obtained across different geographical locations. Dendrogram studied through unweighted pair group method of arithmetic analysis differentiated all the genotypes into two major clusters, Cluster I had the single population of Rajasthan and Cluster II was represented by genotypes of Delhi, Haryana, Madhya Pradesh and Rajasthan. The Kaempferol content ranged from 0.07 to 0.49 mg/g and Delhi population was the highest accumulator.