Breeding strategy for genetic improvement up to four generations in relation to artemisinin with canopy and other secondary metabolites in Artemisia annua L.

摘要

This study represents a classical breeding approach for evaluating and systematically selecting high yielding and specific canopy holding plants through the expression of enhanced secondary metabolite biosynthesizing capability for the pharmaceutically important phyto-molecules-Artemisinin. During the 4 years of study (C0-C4 cycle) it was observed that, plant height ranging from about 100 cm to more than 300 cm, and the plants touching around 300 cm height did fall in the three distinct canopy types i.e., pyramidal, spreading and oval in a population. In C0 cycle artemisinin content was in the range of 0.1-0.2% and artemisinic acid (AA) was high (above 0.03%). Gradually due to high selection pressure in favour of artemisinin content, plants containing high artemisinin content showed low AA (less than 0.01%) in C3 cycle. It was also observed that essential oil did not have any significant relationship with artemisinin content. In C0 cycle, oil content was medium (0.2-0.59%) or low (0.0-0.19%) along with artemisinin content. There was a clear-cut shift from three predominant distinct canopies towards oval and spreading in whole selection procedure and then ultimately going in the favour of the oval canopy type for high artemisinin concentration. In a classical breeding fashion, on the principle of recurrent mass selection and progeny testing, the genetic improvement of population through gene pool exploitation using restricted mating among selected progenies of chemotypically superior plant and high yielding genotype (variety 'CIM Arogya') was developed.