Seed Germination Behavior of Eight Medicinal Plant Species of Sri Lanka

With the increased demand, wild herbal medicinal plants are over exploited from wild populations. Lack of information on seed biology is an impediment in propagation and conservation of these species. Thus, the main aim of the study was to determine the seed germination behavior of eight medicinal plant species from Sri Lanka, assisting their conservation. Seeds were collected from the wet zone of Sri Lanka from at least five individuals from each species. Seed and embryo morphology was recorded. Seed moisture content (SMC) was determined by an oven dry method. Standard hundred seed test was conducted to determine the desiccation sensitivity. Seeds were incubated at 32o and 25o C in light/dark or complete darkness and signs of imbibition were observed. Effect of GA3 and manual scarification on seed germination was studied. Four replicates of at least 12 seeds were used in all experiments. Arcsine transformed data were analysed using one-way ANOVA. Seed size varied from 0.9 to 3.8 cm. Seeds of all the species had fully-developed embryos indicating absence of morphological dormancy. Signs of imbibition were absent in portion of Entada pusaetha, Adenanthera pavonina, Cassia fistula, Urena sinuata and Sida rhombifolia seeds indicating that they were physically dormant (PY). However, manually scarified E. pusaetha seeds have not germinated, indicating the presence of physiological dormancy (PD), i.e., these seeds have combinational dormancy (PY+PD). GA3 treatment, manual scarification +GA3 treatment and warm stratification increased the germination of Salacia chinensis, Calophyllum inophyllum and Madhuca longifolia seeds, respectively indicating that they also have PD. SMC suggested that S. chinensis, E. pusaetha, A. pavonina, C. fistula, U. sinuata and S. rhombifolia seeds have orthodox storage behavior, while the results of the hundred seed method indicated that C. inophyllum and M. longifolia seeds as recalcitrant and orthodox, respectively. Seed germination pattern of A. pavonina, and S. rhombifolia after storage suggested a possible occurrence of sensitivity cycling phenomenon. Storage breaks the dormancy of C. fistula, U. sinuata, S. rhombifolia (dry storage) and A. pavonina (Wet storage) seeds while GA3 was successful in relieifing dormancy of C. inophyllum (after scarification), M. longifolia and S. chinensis seeds.Keywords: Orthodox, Physical dormancy, Physiological dormancy, Recalcitrant, Seed propagation, Storage behavio

Radical Anatomy, Seedling Morphology and Host Detection of Seedlings of Cassytha filiformis

Seed biology is foster for ecologically sound management of parasitic weeds. The seedlingwhich is the first vegetative phase of a plant after the germination has particular importancein the study of seed biology. Distance of parasite from the host plant, and germinationmorphology are two important aspects in life cycle of a parasitic plant. However, the littleattention has been given to the study of germination biology of Cassytha filiformis. Thus, mystudy was conducted to identify the radical anatomy, seedling morphology, and minimaldistance of the host to successful attachment of C. filiformis.Manually scarified seeds were allowed to germinate on moisten filter papers and germinatedradicals were collected in FAA solution and were used to study the anatomy of radicle usingmicrotome sectioning. Another sample of seedlings was allowed to grow further andphotographs were taken at different developmental stages. Some of selected seedlings wereplanted in soil media which are placed in three different distances from the host plants (5 cm,10 cm, and 15 cm) and number of attached seedlings to their host and maximum days ofsurvival without the aid of host was determined.Anatomy of radical was similar to the general anatomy of typical dicotyledonous plant rootwhich consist of outer epidermis, cortex and steal with an outer pericycle. After 5-6 days thisis differentiated into 4 adventitious roots. A yellowish, conical hypocotyl is developed ascontinuous event of germination and this curved and formed a n-shaped loop in order toattach the substratum and to raise the cotyledon up. Thus the germination type is epigeal.According to the observations 100% of seedlings were attached to their respective host whichwas placed in 5 cm distance whereas about 60% of seedlings were able to attach where hostwas in 10 cm distance. 94% of seedlings were failed to attach their hosts in 15 cm distance.Attachment rates between 5cm, 10cm and 15cm differ significantly (F= 20.14, p<0.001).Thus the minimal distance for successful attachment, host plant should be ranged from 5cmto 10 cm. And the seedlings can survive for about eight weeks without attaching a host usingstored food reserves.

Seed Biology of Three Strychnos Species (Loganiaceae) from Sri Lanka, Towards Their Conservation

Knowing seed germination phenology is important in propagation and thus conservation of plant species as many of the plants regenerate through seeds naturally and easily. Knowledge on seed biology of a species plays a vital role in both ex-situ and in-situ conservation. Thus, we aimed to study seed biology of three Strychnos species from Sri Lanka which are of conservation importance, S. potatorum L.f. and S.nux-vomica L. in dry zone and S. benthamii C. B. Clarke in wet lowlands and montane regions. Seed moisture content was determined for study species by an oven dry method. Desiccation sensitivity of seeds was determined using 100 seed method proposed by Pritchard et al. (2004). Effect of different temperatures (32 and 25o C) and Gibberellic acid (GA3) concentrations (500 and 100 ppm) on seed germination was evaluated. Seeds were incubated in Petri dishes on moistened (with distilled water or GA3) tissue papers in light/dark (12/12hr) condition. Embryo length: seed length ratio (E: S ratio) of fresh seeds, seeds just after radicle emergence and of seeds before shoot emergence was studied. The moisture content of S. nux-vomica, S. potatorum and S.benthamii at dispersal was 42.02, 34.9 and 45.93%, respectively. Hundred seed test for S. nux-vomica, and S. potatorum revealed that their seeds could tolerate desiccation, while S. benthamii seed could not survive desiccation. Radicle emergence of S. nux vomica and S. potatorum incubated at 32o C initiated after 34 and 59 days, respectively. Radicle emergence of S. benthamii initiated after 11 days at 25o C. GA3 treated seeds of S. nux-vomica and S. potatorum emerged radicle quickly than those incubated on distilled water (p<0.001and p<0.001, respectively), while there was no GA3 effect on S. benthamii seeds. Further, when the shoot emergence was considered a considerable delay in shoot emergence was observed in seeds of all the three species indicating that they have epicotyl dormancy. The size of the embryos of S. nux vomica, S. potatorum and S. benthamii seeds have increased by 38.24, 34.48 and 25.49% by the time of radicle emergence. Thus, seeds of the three study species also have a morphological component to their dormancy. Thus, their dormancy can be classified as morphophysiological epicotyl dormancy. Although the GA3 has increased the shoot emergence rate, seeds of all the study species emerged shoot within 4 months. Thus, we recommend sawing of seeds 4 months prior to seedling requirements to obtain necessary seedlings for seed restoration. Determination of dormancy type and storage type of these species is vital in seed handling and storage for restoration activities.Keywords: Strychnos, Morphophysiological, Epicotyl dormancy, Seed dormancy, Seed storag

Seed Germination and Dormancy of Psychotria gerdneri as a Dominant Forest Species of Tropical Montane Forest in Sri Lanka

Tropical Montane forest in Sri Lanka is rich in endemism and biodiversity. However most ofmontane forests are degraded as result of natural and anthropogenic activities. SincePsychotria gardneri is a very dominant endemic species in Sri Lankan montane forest,knowledge of seed germination and seed Dormancy is very essential in restoration activities.Fully ripen seeds of P. gardneri were collected from Hantana forest range (altitude: 1,000-1,250 m). Seed: embryo ratio was taken of ripen and germinated seeds, water imbibition ofseeds of non-scarified and manually scarified were measured and tests of standardgermination and gibberellic acid (GA) treatment were conducted to identify the dormancyclasses. Seed germination under light/ dark and dark condition were tested to identify thegermination requirement.Embryo: seed ratio of ripened seeds and germinated seeds was 0.5 and 0.7 respectively.Water Imbibition pattern was similar in both non-scarified and manually scarified seeds. Seedstarted their germination within 15 days and 50% of seeds germinated within 65 days forstanders germination. 53% of seeds germinated within 28 and 38 days respectively for 100ppm and 500 ppm of GA. Under the fully dark condition 57% seeds germinated within 56days.P. gardneri has a combination of morphological and physiological dormancy. 100 ppm GA isa suitable treatment for breaking the physiological dormancy. Although Light is not agermination requirement, dark condition has enhanced the germination of P. gardneri. If weuse bulk of seed to get seedling of P. gardneri for restoration purposes, treating of seeds with100 ppm GA is a best option. If not seeds should be sown in more than 65 days in wetmedium.

Reinstating Soil Biodiversity: The Key for Converting Degraded Lands to Sustainable Systems

Lost soil biodiversity in croplands can be reinstated by using microbial biotechnological methods. Conventional agricultural practices collapse diversity of soil microbial communities. This may lead to decline in crop productivity and sustainability. Direct application of developed fungal-bacterial communities known as biofilmed biofertilizers (BFBFs) has been introduced recently, which reduces the chemical fertilizer usage with other crop and soil benefits over conventional biofertilizers. This study investigates the effect of BFBFs on microbial diversity and introduces them as a remedial measure to recover degraded croplands. A degraded tea soil was separated in to particle size fractions and transferred to trays that were arranged in a completely randomized design with three replicates in a greenhouse. Biofilm-T, the BFBF developed for tea was used with a control (distilled water). Certain soil biological and chemical properties were measured after three months of incubation. Application of Biofilm-T significantly increased pH in fine fraction. Available nutrient contents varied in the soil fractions. Furthermore, addition of Biofilm-T significantly increased bacterial abundance in clay fraction due to dormancy breaking of microbial seed bank by the BFBF-specific biomolecules. Total carbon and nitrogen contents were significantly high in fine and clay fractions due to presence of higher algal and cyanobacterial growth. This study concludes that application of BFBFs breaks dormancy of microbial seed bank trapped in different soil fractions and also assists in improving nutrient release from them, thus reinstating soil biodiversity and sustainability of degraded croplands.Keywords: Agriculture, Biofilm biofertilzer, Micorbial biofilms, Microbial diversity, Soil healt

Propagation of three important medicinal plants in Aacanthaceae; <em>Andrographis paniculata</em>, <em>Barleria prionitis</em> and <em>Rhinacanthus polonnaruwensis</em>

High demand has increased the exploitation of medicinal plants from the wild. Insufficient information on germination and seedling development hinders the propagation of such plants. Thus, seed germination and seedling development of three medicinal species in the family Acanthaceae were studied. Seeds were collected during their peak dispersal period. Seed moisture content (SMC) was determined using the oven dry method. Seed germination and effect of 500 ppm GA treatment and dry storage on germination were studied. Seedlings were transferred to three potting media, viz, sand: coir dust: compost, sand: compost, sand: coir dust and sand: garden soil (in equal ratio) and raised until 45 days in a greenhouse. Number of leaves and height of plants were measured in 7-day intervals. Fresh weight, root, shoot and leaf dry weights were measured after 45 days. SMC of all the studied species was &lt; 15%, revealing that they are orthodox. Thus, no special conditions are needed to store them. Rhinacanthus polonnaruwensis seeds had a T50 &lt; 30 days, indicating that they have no dormancy. Barleria prionitis and Andrographis paniculata seeds were dormant as the T50 was &gt; 30days. Germination increased &gt; 80 % after GA3 treatment and dry storage. Therefore, seeds of B. prionitis and A. paniculata have non-deep physiological dormancy. Dry storage for 1 and 3 months could be recommended for these two species, respectively. Seedlings of all three-study species showed high growth performance in the sand: garden soil potting medium which could be recommended to grow these species. These information will be useful to germinate and grow these three species for large-scale commercial pursoses

Sri Lanka is a hot spot for illegal transnational trading of biodiversity and wildlife materials from South Asian region

Trafficking of biodiversity materials have been regarded as a major threat to the ecological balance on earth and Sri Lanka is not spared on that too. This paper describes the protocol in the context of illicit trade in biodiversity and wildlife materials trade products across Sri Lanka during the period of 1992–2009. Further this paper highlights which can be effective to counter attack and save the illegal transnational trading and how the region could approach a coordinated implementation of those key provisions. Details of the current illegal biodiversity during that period was highlighted and Sri Lankan Customs great effort on protect the countries pride on conservation of biodiversity and weak points of illegal transaction was pointed out clearly with remedies