INVESTIGATION OF SEED PROPAGATION METHODS AND SEED BIOLOGY OF THE MEDICINAL LIANA Coschnumfenestratum Colcbr (Menispermaceae)

Abstract

Caseinftum fenestroinum colcbr. (Mcnispcmuiccae) a dioecious liana, common in disturbed forest of low country wet zone. It is a widely used medicinal liana in Sri Lanka and a potential foreign market, due to the presence of alkaloids such as berberinc. jatrorhhizine and palmatine in it, While the water extraction of its stem provieds a decoction for treatment or body aches, pains, common colds, tetanus, dressing wounds and ulcers because of its antiseptic properties. As a result of illegal over exploitation, distructive collection, relatively slow growth rate,seed predution, low seed germination and low percentage of seedling survival, natural populations of this species are decimated and for are disappearing at an alarming rate. To meet the increasing demand and over come short supply of this species, development and simple cost effective propagation techniques is one of the primary impediments for mass cultivation. Seeds of this species show relatively long period of dormancy (2-15 months) and under natural conditions seed germination were found to be less titan 20 %. This study examined tow C fenestronum seeds could be propagated using simple and cost effective methods and attempts were made so develop techniques to overcome seed dormancy. C, fenestronum fruits were collected by bagging the mature fruit bunches still intact to the parent liana from disturbed forest fringe in Sinharaja MAB Reserve, Fruits were depulped manually and s washed w lilt tap water before Use seeds were used for a range of experiments. The moisture content of fresh seeds was 31= 0.61 % and the subsequent moisture loss of seeds stored under different conditions such as in a humid chamber, polythene sealer bags,paper bags and in open areas were examined, The experimental design was a random feed block design U recreates; n = 020. The experiments were aimed £ out under laboratory conditions were the average moisture content was76=1.39 %The higest moisture loss was when seeds were stored to open areas and the lowest was found to be when seeds were stored in humid chamber, Seeds stored for 40 days were examine for viability under humid condition and room condition Viability was 89% under humid condions and it was 30% under room condition, Seeds of C fenestranuw were categorized under "recalcitrant seed" tacking in to consideration of the initial moisture content, moisture losses and viability. Bioassays carried out using seeds of Brassicajwrceae revealed presence of germination inhibitors in C fenestranuw seeds (endosperm & the embryo). B junceae seeds were the germinated on blotting papers soaked in 5% water extracts of embryo. Germination Germination percentage of B.Junceae grown on endosperm and embry extracts were 17% and 25% respectively while 80% and 88% germination percentage was observed in control where the blotting paper was soaked in water. Seed germination experiments were carried out under plant house conditions (maximum light 800 pmorV3 and Relative humidity 81&l%). The experimental design was a completely randomized design (3 replicates; n - 20). Seed experiments in order to evaluate the seed germination, seed soaked in gibberllie acid 1500 ppm, 2000 ppm, 2500 ppm and 3000 ppm concentrations, the mechanical treatments ineluded .cracking of the seed coat, soaking in tap water and distilled water for 12-24 hours, seed exposure to sunlight followed by soaking in tap waier. Another set of seeds (n = 60) collected firpm forest floor were soaked in gibberllic acid 2000 ppm, Of ibis experiments C fenestranum seeds collected from the forest floor & subsequently treated with gibberllic add 2090 ppm gave the best germination percentage 27%. Compuison of wood anatomy and morphology in C fenestranum and Ananirata cocculus, which ts commonly used as a substitute for C fenestranum was carried out by using the cross sections obtained from a range of stem diameter classes (I cm, 2 cm, 3 cm) of there two species, for study woods stems of both species show ed anomalous growth, But in A cocculus anomalous growth was present in secondary wood structure and in C fenestranum it was absent, The both ihiekness o f C fenestranum was lower than A cocculus Vessels diameter of A (20.3 =1.5 pm) was higher than C fenestranum (19.03 =2.5 pm)