以基因體育種策略開發水稻白葉枯病及稻熱病之耐久抗性品種

Genomic Breeding-Developing Rice Variety with Durable Resistance to Bacterial Leaf Blight and Blast Diseases

王子明(Arthur Z. Wang) ； 王強生(Chang-Sheng Wang)

《農林學報》 58卷1期 (2009/03) Pp. 11-24

https://doi.org/10.30089/JAF.200903.0002

摘要

抗病育種是作物病害防治的最根本策略及最環保作法。當大面積栽培單一抗病品種將會提高田間稻熱病病原菌的生存壓力，迫使病原族群產生變異，使得推廣作物品種喪失抗性。因此，水稻抗病育種的最終目標是育成具耐久抗性(durable resistance)品種。雖然歷經多年種原抗性檢定，目前仍無法找到具廣幅抗性(broad-spectrum resistance)稻種。實際上，以雜交育種方法要堆疊多個抗病基因(gene pyramiding)有極高的難度，而且同時進行不同病原菌及其生理小種的病害檢定更是龐大的工作。自從分子標誌輔助選拔(molecular marker-assisted selection, MAS)的選拔方法發明後，解決了上述的問題。以抗白葉枯病基因及抗稻熱病基因為例，利用分子標誌輔助選拔進行雜交後裔族群的篩選，能有效地自雜交後裔族群中篩選出具有抗病基因的個體，並可縮小病原菌接種的試驗規模，快速地育成堆疊抗病基因的品系。此外，隨著導入抗病基因數目的增加，發現抗病基因的作用力可以有效地累加，並可穩定地遺傳。依據對堆疊抗病基因近同源系的抗性分析，可得知導入一個抗性較高的基因，並搭配2至3個抗病基因，即可達成耐久抗性的目標。藉由對抗病基因群(resistance gene analogs, RGAs)構造的探討，育成耐久抗性品種或設計抗特定生理小種的品種是可行的。

關鍵字

耐久抗性 ； 稻熱病 ； 白葉枯病 ； 基因堆疊 ； 基因體育種

並列摘要

Breeding disease resistant variety is the best policy for crop disease management and the best practices of environmental protection. Generally, cultivation of a blast resistant variety in large-scale induce higher survival pressure to cause mutation in blast fungus Magnaporthe grisea that generates new virulence and enhances pathogenicity to result in resistance losing quickly in popular variety. Therefore, development of durable resistance variety is considered to be the final goal of rice disease resistance breeding. No germplasm was found to be broad-spectrum resistant after years of resistance investigation. Up to date, it is very difficult to pyramid resistance genes in one variety by cross hybridization because of the difficulties in challenging and investigation using various pathogens (races) at the same time. The marker-assisted selection (MAS) method brings a resolution to the above breeding problem. The application of MAS in rice bacterial blight resistance and rice blast resistance breeding programs showed it is efficient in selecting individuals containing resistance genes from a crossing population, reducing the scale of subsequent experiment, and breeding variety with pyramided genes. The resistance of disease was found to be proportional to the number of resistance genes in one individual suggesting that the resistance genes can be stacked, inherited and conferred resistance during generations. According to the results using near isogenic lines, durable disease resistance variety can be bred by introducing a strong resistance gene together with 2 to 3 other resistance genes. Future analysis on molecular structure of resistance gene analogs (RGAs) will be benefit to the breeding of durable and race-specific resistance variety.

並列關鍵字

Durable resistance ； Rice blast ； Rice bacterial leaf blight ； Gene pyramid ； Genomic breeding