Collection of Millet Germplasm in Sri Lanka and Thailand

雑穀類は, イネ, ムギ等のような多量生産を行う穀類以外を総称していう言葉である。今回の探索収集では, 禾穀類の中の小粒作物 (アワ, キビ, ヒエ等, ミレットと言われる) を中心に, モロコシ, トウモロコシ等も収集した。ミレットは, 古くからユーラシア大陸或はアフリカ大陸において広く栽培され, 受け継がれてきたが, 近年, 生産性や収益性の高い作物に置き代わり, 急速に耕地から姿を消しつつある。今回は, 特にインドを中心としていまなお広く栽培されているシコクビエ, アワ等のミレットを中心に, 数種類の雑穀類をスリランカ及びタイ北部から収集した。収集した系統のほとんどは各地域の農家において古くから栽培されてきた在来種である。本探索により, 48点のシコクビエ (Eleusine coracana), 23点のアワ (Setariaitalica), 6点のキビ (Panicum miliaceum), 8点のモロコシ (Sorghum bicolor), 9点のトウモロコシ (Zea mays) を収集した。また, ミレットとの混作作物或は隣接した畠の作物も一部収集した。全収集数は106点で, そのうち89点はスリランカで, 17点はタイで収集した。中部及び南部スリランカにおいて, 標高Omから約2,000mの地域を延べ1,475kmに渡り探索し, 作物の生育データと共に種子を収集した。スリランカにおいては, 植物遺伝資源センターが独自に探索収集を行っていたので, 同センターの収集リストを照合し, 探索集落に重複を生じないように配慮した。シコクビエは乾燥・半乾燥地帯の焼畑等において広く栽培されていた。収集したサンプルには穂の形や大きさ, 節の色等に変異が認められた。混作が多く, 混作作物にはアワ, ナ類等色々であった。キビの栽培を見かけることは非常に少なく, 主として農家の保存種子の分譲を受けた。豆類等隣接畑から収集したものもあった。シコクビエはいわゆる "うす焼き" あるいはペースト状にして食べるということであった。アワはお粥として食べるのが一般的のようであった。農家は雑穀, 野菜等の作物の種子をよく保存しており, 古くから集落に伝わる在来種が多かった。スリランカには今回を含めても未収集地域が多くあり, 今後とも収集が必要である。北部タイにおいてはミレットの食用としての栽培は急減していた。作期ではないこともあってか, 栽培畑に巡り会うことはなかった。小数部族の集落を訪ね, 農家が保存している穂や乾燥中の穂から種子を収集した。収集物はモロコシ, トウモロコシがほとんどであった。北部タイのミレット収集を計画する場合, 北西部のカレン族, 北東部のリス族等が住む, より深い山岳地帯に足を踏み入れる必要があると考えられた

Enabling trade in Gene-Edited produce in Asia and Australasia: The developing regulatory landscape and future perspectives

Genome- or gene-editing (abbreviated here as ‘GEd’) presents great opportunities for crop improvement. This is especially so for the countries in the Asia-Pacific region, which is home to more than half of the world’s growing population. A brief description of the science of gene-editing is provided with examples of GEd products. For the benefits of GEd technologies to be realized, international policy and regulatory environments must be clarified, otherwise non-tariff trade barriers will result. The status of regulations that relate to GEd crop products in Asian countries and Australasia are described, together with relevant definitions and responsible regulatory bodies. The regulatory landscape is changing rapidly: in some countries, the regulations are clear, in others they are developing, and some countries have yet to develop appropriate policies. There is clearly a need for the harmonization or alignment of GEd regulations in the region: this will promote the path-to-market and enable the benefits of GEd technologies to reach the end-users

Components of Quantitative Resistance to Anthracnose (Colletotrichum Gloeosporioides) in Tetraploid Accessions of the Pasture Legume Stylosanthes Hamata

Partial resistance to the anthracnose pathogen Colletotrichum gloeosporioides was characterised in 6 tetraploid accessions and cv. Verano of the tropical pasture legume Stylosanthes hamata. Four components of resistance (incubation period, latent period, spore production, weighted infection type) were determined and compared with those of the susceptible S. scabra cv. Fitzroy. There were significant differences between the accessions for all resistance components. The mechanisms of resistance in the 3 most resistant accessions appeared to be different, with accession 55830 having a longer incubation period but higher sporulation per day than either 92715 or 92412. Spore production, weighted infection type, and latent period were significantly (

Glasshouse and field evaluation of quantitative resistance to Colletotrichum gloeosporioides in tetraploid accessions of Stylosanthes hamata

A total of 20 field isolates of Collectotrichum gloeosporioides from Stylosanthes hamata was tested for pathogenicity and differential virulence in glasshouse inoculation experiments. No pathogenic specialization towards S. hamata was noted, but all three major races of the pathogen causing Type A disease were detected using the host differential set of one S. viscose and four S. scabra accessions. There was also little evidence of pathogenic specialization to S. hamata when 37 accessions were inoculated with three isolates representing the three main Type A races on S. scabra and a field isolate from S. hamata cv. Verano. The resistance of 38 accessions of S. hamata, including cvv. Verano and Amiga, was evaluated by inoculating field plots with a mixture of four isolates of C. gloeosporioides. Anthracnose progress was monitored by regular disease assessments and accessions were compared using the terminal disease severity, the rate parameter of logistic and linear models of disease progress and the area under the disease progress curve (ADPC). Accessions showed a continuous range from moderate to high resistance, with Verano and Amiga taking intermediate values. Spearman rank correlations among ADPC, terminal severity in the field, apparent infection rate and the severity in glasshouse tests were generally significant. Several resistant accessions were identified with potential for use in a breeding program to improve the anthracnose resistance of cvv. Verano and Amiga

Fontes de resistência em acessos de Solanum (secção Lycopersicon) a Verticillium dahliae raças 1 e 2 Sources of resistance to Verticillium dahliae races 1 and 2 in accessions of Solanum (section Lycopersicon)

A murcha-de-verticílio (Verticillium dahliae) é uma das doenças mais severas do tomateiro (Solanum lycopersicum L.). Duas raças fisiológicas de V. dahliae foram caracterizadas infectando o tomateiro e ambas estão presentes no Brasil. A estratégia de controle mais efetiva para isolados da raça 1 tem sido a utilização de cultivares resistentes em associação com práticas culturais. Entretanto, não existem cultivares comerciais de tomate resistentes à raça 2 do patógeno. Neste contexto, torna-se importante a identificação de novas fontes de resistência que sejam efetivas contra as duas raças de V. dahliae. Buscou-se fontes de resistência a isolados de V. dahliae (raças 1 e 2). Cem acessos de uma coleção de germoplasma contendo espécies cultivadas e selvagens de Solanum (secção Lycopersicon) foram inicialmente inoculados pelo método de imersão de raízes com um isolado de V. dahliae raça 1 (5 mL de uma suspensão de 10(6) conídios/mL) em condições de casa de vegetação. A avaliação foi feita aos 30 dias após a inoculação, usando uma escala de notas variando de 1 (planta sadia) a 5 (planta morta). Foram considerados resistentes os acessos que apresentaram nota média entre 1 e 2. Um grupo composto por 38 acessos classificados como resistentes neste primeiro ensaio foi reavaliado para resistência a outros quatro isolados de V. dahliae pertencentes às raças 1 e 2. As cultivares Ponderosa e Floradade foram utilizadas como controles. O ensaio foi conduzido em casa de vegetação em delineamento experimental de blocos ao acaso em arranjo fatorial 5 x 40, com três repetições (vasos com quatro plantas). A avaliação foi feita baseada nos parâmetros epidemiológicos: período de incubação e índice de doença. Foram identificados acessos com resistência raça-específica e também com resistência a ambas as raças. Estes acessos podem ser indicados para futuros programas de melhoramento genético visando incorporar resistência ampla à doença.<br>Verticillium wilt (Verticillium dahliae) is one of the most destructive diseases of tomato (Solanum lycopersicum). Two V. dahliae races have been described infecting tomatoes and both are present in Brazil. The most effective control strategy of V. dahliae race 1 isolates is based upon the use of resistant cultivars combined with cultural practices. However, there is so far no fresh-market tomato cultivar available with resistance to V. dahliae race 2. Therefore, it is important to identify new sources of effective resistance against both pathogen races. Solanum (section Lycopersicon) accessions were screened to search for resistance sources to both V. dahliae races 1 and 2. A germplasm collection composed by 100 accessions of cultivated and wild tomatoes was first inoculated via root dipping method (5 mL; 10(6) conidia/mL) with one isolate of V. dahliae race 1. Disease assessment was done 30 days after inoculation using a disease severity index ranging from 1 (plant without symptoms) to 5 (dead plant). Accessions with average severity index from 1 to 2 were classified as resistant. A subgroup of 38 race 1 resistant accessions was re-evaluated against four isolates of V. dahliae belonging to races 1 and 2. The cultivars Ponderosa and Floradade were used as controls. The assay was conducted under greenhouse conditions using a completely randomized, factorial (5 x 40) design with three replicates (three pots with four plants each). Evaluation was done based upon two epidemiological parameters: incubation period and disease severity index. Race-specific and multiple-race resistance sources were identified. The most promising accessions could be useful for breeding purposes aiming to develop cultivars with stable resistance to both races