Jpn.J. Trop. Agr. 46(1):14-22, 2002 Surveying and Mapping of Wild Species of Oryza in Sri Lanka Athula Somakumara Udagama LIYANAGE*1,Ponna Vattage HEMACHANDRA*1, Damayanthi Kanthilatha EDIMSINGHE*1,Sarath Kumara SENEVIRATHNA*1and Junji TAKAHASHI*2 *1 Plant Genetic Resources Center, P.O.Box 59, Gannoruwa, Peradeniya, Sri Lanka *2 Institute for International Cooperation, Japan International Cooperation Agency, 10-5, Ichigaya Honmura-cyo, Shinjuku-Ku, Tokyo 162-8443, Japan Abstract Sri Lanka is considered to be a secondary center of eco-genetic diversity for many crop species. It exhibits a rich floristic diversity distributed over a variety of bio-climatic environments. Sri Lanka's natural forests and protected wetlands harbor all the wild relatives of rice found in the country. Systematic exploration and collection missions specific to wild relatives of rice were initiated by the Central Agricultural Research Institute (CARI) in 1988 in collaboration with the International Rice Research Institute (IRRI). One result was the discovery of O. rhizomatis, a new species endemic to Sri Lanka. Survey, exploration and collection of wild rice germplasm in the target areas were conducted during the period of December 1998 to May 1999 by the Plant Genetic Resources Center (PGRC). The distribution of the 5 wild species of rice occurring in Sri Lanka is depicted in the maps. Their habitats are also described in this paper. Key words Oryza eichingeri, Oryza granulata, Oryza nivara, Oryza rhizomatis, Oryza rufipogon, Sri Lanka ス リ ラ ン カ に お け る 野 生 イ ネ 属 の 調 査 と マ ッ ピ ン グAthula Somakumara Udagama LIYANAGE*1 , Ponna Vattage HEMACHANDRA*1, Damayanthi Kanthilatha EDIRIsINGHE*1, Sarath Kumara SENEVIRATHNA*1・ 高 橋 順 二*2 *1Plant Genetic Resources Center, P.0.Box 59, Gannoruwa, Peradeniya, Sri Lanka *2国 際 協 力 事 業 団,国 際 協 力 総 合 研 修 所 〒162-8443東 京 都 新 宿 区 市 ヶ 谷 本 村 町10-5 要 約 ス リ ラ ンカ は 多 くの 作 物 に とっ て 多 様 性 の 第2次 中心 地 とみ られ て い る.ま た,広 範 な生 物 気 候 環 境 下 に お い て,豊 富 な 植 物 多 様 性 が み られ る.ス リ ラ ン カ の天 然 森 林 と保 護 され た湿 潤 地 で は,ス リ ラ ン カ に あ る全 て の 野 生 稲 が み られ る. 中央 農 業 研 究 所(CARI)に よ る体 系 的野 生 稲 の 探 索 ・収 集 は,1988年 の 国 際 稲 研 究 所(IRRI)と の 協 同 研 究 と して始 ま っ た.そ の 結 果 と して,新 し くス リ ラ ン カ 固有 の種,O.rhizomatisが 発 見 され た. 1998年12月 か ら1999年5月 ま で,野 生 稲 の 探 索 ・収 集 ・調 査 が 植 物 遺 伝 資 源 セ ン ター(PGRC)に よ り行 わ れ た.野 生 稲5種 の 分 布 地 図 が作 成 され た.ま た,そ れ らの 生育 環 境 を明 ら か に した. キ ー ワ ー ド ス リ ラ ンカ,Oryza eichingeri, Oryza gyanulata, Oryza nivaya, Oryza rhizomatis, Oryza rufipogon G.H.K. THWAITESand L.T. LESCHENULTfrom the Introduction Colombo Lake in the western province and Sri Lanka exhibits a rich floristic diversity, Kurunegala area in the northwestern province distributed over a variety of bio-climatic environ- respectively, is more than 125 years old. Various ments. It has a well-balanced collection of the collectors added accessions to the herbarium nearly 3500 species of flowering plants, ferns collection during the 1960's and 1970's. The and other groups living in climax communities National Herbarium covers the distribution of spread over the country. About 830 species of wild species in over 40 locations across all the endemic vascular plants grow in this country.2) bio-climatic zones in the country, except at high No record was available on regard the elevations over 1000 m above sea level. collection of wild rice germplasm in Sri Lanka The IRRI/IBPGR field collector was able to until the mid-nineteen when wild and weedy rice gather 14 wild rice accessions in the 198384 began to be collected as components of the rice Maha season5). One of the authors (A.S.U.L) of genetic resources program. Most of these this paper also collected 8 wild rice samples in samples were collected in close proximity to the year 19856). cultivated fields.2) The first record of wild rice According to CHANG,4)the Asian annual according to the National Herbarium record, cultigen rice (O. sativa) originated in a broad namely Oryza eichingeri, collected in 1868 by area stretching from the southern foothills of Received Apr. 20, 2001 the Himalayas to Southeast Asia and Southwest Accepted Nov. 9, 2001 China. The eco-geographical race Indica spread LIYANAGEet al.: Survey & Mapping of Wild Oryza in Sri Lanka 15 southward to India and Sri Lanka and the Malay rainfall ('Maha•fseason) and the southwestern Archipelago and northward into central and monsoon (May to September), which brings south China. Most of the rice cultivars found in precipitation mainly to the southwestern part Sri Lanka belong to the Indica type. ('Yala•fseason). The annual rainfall varies from The present status of the Sri Lanka form of 2,500 mm to over 5,000 mm in the southwestern the 0. officinalis complex is still unclear8). part of the island while in the northeastern and However, some authors reported that the Sri southeastern parts the annual average is less Lanka form was within the range of variation of than 1.250 mm.5 0. eichingeri Peter, an African species of the ) The selected areas for survey and exploration same complex.3) were located in the Ruhunu National Park These wild relatives of rice constitute a (RNP) and forest areas of the Ratnapura, major genepool for rice improvement, could Anuradhapura, Puttalam, Polonnaruwa, Hamban- provide new sources of resistance to pests and tota and Monaragala districts. The target areas diseases by the use of techniques for the transfer also extended to other districts except for the of genes from wild rice to cultivated rice. districts belonging to the North and East for However, genetic erosion of the wild species is security reasons. Furthermore, a survey was occurring in many areas in the country and conducted in some of the bordering villages of populations of wild rice are continuously being the Polonnaruwa, Anuradhapura and Puttalam destroyed. Therefore it is important to conserve districts. these wild species for future research and The collections were performed mainly breeding purposes. along the road. Seeds were collected from the This study aims at surveying and mapping population if they had matured on the plant. Live wild species of Oryza for conserving genetic plants were collected in order to grow in green resources in the Gene bank for future breeding houses for seed conservation. work. Locations where wild species of rice were found were marked by using a Global Positioning Materials and Methods System (GPS) for further collection and also Before the study, the distribution of wild periodic monitoring of the populations. Data were rice was surveyed using records at the National collected such as altitude, EC of water, water Herbarium and records in the Department of temperature, etc. Agriculture (Fig. 1) in order to make plans for the Morphological characteristics were used to explorations. Wild forms of Oryza are growing identify wild rice species. Basic morphological in all the agro-climatic zones. Considering characters are presented in Table 1. ecological parameters such as rainfall, vegeta- Results and Discussion tion and soil and present land use, Sri Lanka is divided into three major agro-ecological zones, A total of 127 samples of wild relatives of e.g. (a) wet zone, (b) intermediate zone and (c) Oryza were collected during the period from 14 dry zone. Sri Lanka receives rain mainly from December 1998 to 20 March 1999. The collection two monsoons. The northeast monsoon (Decem- sites of the 5 wild species of rice, namely O. ber to February), which causes Island-wide nivara, O. rufipogon, O. eichingeri, O. rhizomatis Table 1. Basic morphological characters of wild rice Source: The Wild Relatives of Rice10) 16 Jpn. J. Trop. Agr. 46 (1) 2002 and O. granulate are depicted in Fig 2. Table 2 Low-tillering to very high-tillering popula- shows the ecosystem types for Oryza species tions was observed and some populations were found in Sri Lanka until the present. The partially sterile. Types with red-and straw-colored Appendix shows the collection data for all the awns were observed. Villagers seldom collected samples. Major observations are described below. seeds of this species. However, it was reported that in the year 1963, people of the Trincomalee Oryza nivara district collected these seeds for food7). Around 40%of the collected samples consisted of O. nivara in this survey. O. nivara was mainly Oryza rufipogon distributed in the low country dry and intermedi- Herbarium records indicated that some of ate zones (Table 3). It was collected at low altitudes the samples were collected in the dry zone. (Table 4). It was not found in the wet zone or However, no samples were found in the dry upcountry dry/wet regions. O. nivara grows zone at this time (Fig. 2). Most of the populations extensively in the North Central Province, where of this species were distributed mainly in parts the area covered by some of the populations of the wet zone in Sri Lanka (Table 2) and they exceeded 2 ha.