ABSTRACT
Randomly amplified polymorphic DNA (RAPD) markers were used to estimate genetic diversity among 18 cultivars of niger from India. Total genomic DNA was extracted and subjected to RAPD analysis using 80 arbitrary 10-mer primers; 17 primers were selected, which yielded a total of 124 bands, 41.20 percent of them polymorphic. None of the primers produced unique banding pattern for each cultivar. RAPD data were used to calculate a Squared-Euclidean Distance matrix which revealed a minimum genetic distance between cultivars JNC-6 and N-48 and a maximum distance between IGP-76 and JN-30. Based on the distance matrix, a cluster analysis was done using a minimum variance algorithm. The dendrogram generated, based on Wards method, grouped 18 niger cultivars into two major clusters. The first cluster consisted of early maturing cultivars (e.g. N-129 and N-134; 80-90 days), and the second of late maturing cultivars (e.g. GA-8 and GA-9; 135-145 days). The present study shows that there is high diversity among the niger cultivars tested and indicates the potential of RAPD markers for identification and maintenance of niger germplasm for crop improvement purposes.
Subject(s)
Crop Production , Asteraceae , Genetic Variation , India , Plant Oils , Random Amplified Polymorphic DNA TechniqueABSTRACT
It is suggested that maternal parent and offspring have conflicting interests over the extent of resource allocation to developing seeds. While maternal parent would be selected to allocate her resources optimally among her offspring, the latter would be selected to demand more. In animals, offspring are known to demand additional resources either visibly (through intense vocal calls) or subtly through the production of hormones. In plants though parent offspring conflict over resource allocation has been invoked, the mechanism through which the parent and offspring interact in regulating resource allocation into developing seeds is not yet clear. In this paper, we propose that the strategies and counter–strategies of the offspring and mother during the development of seeds might be manifested through the production of appropriate growth hormones. Accordingly, we predict (i) hormones that mobilize resources into seeds (e.g. auxins and gibberellic acid) shall be synthesized exclusively by the offspring tissue and (ii) hormones that inhibit resource flow in to seeds (e.g. abscisic acid) be produced exclusively by the maternal tissue. We show that these predictions are supported by existing literature on the temporal dynamics and source of production of growth hormones during seed development. Finally, we suggest that such analysis viewing the production of different hormones during early seed development, as strategies and counter–strategies of mother and offspring tissue, helps ofer a meaningful interpretation of the otherwise complex dynamics of hormone fluxes.
ABSTRACT
Maintenance of pupillary dilatation is necessary for success of scleral buckling procedures. The efficacy of 0.03% flurbiprofen in preventing intraoperative miosis was evaluated by a prospective randomized, double-masked controlled trial of 60 patients. Thirty patients received 0.03% flurbiprofen 6 times at 15 minute intervals 90 minutes preoperatively in addition to the routine dilation regimen. The treated group had a mean pupillary decrease of 1.88 mm and the control group had a decrease of 1.57 mm (p > 0.05). Flurbiprofen did not affect the pupillary size at any step of the surgery. Factors such as age of the patient, lens status, number of cryo applications, duration of surgery, and the size and extent of buckle were assessed. The use of flurbiprofen did not affect the mean pupillary change for any of these groups. Preoperative use of flurbiprofen does not significantly decrease intraoperative miosis during scleral buckling procedures.