Annual Report 2010–11

25 Homecoming of Soybeans Genetic technology is a powerful tool not only for medical researchers, but also for agricultural scientists. Led by its director Prof. Samuel S.M. Sun and deputy director Prof. Lam Hon-ming, the State Key Laboratory of Agrobiotechnology at CUHK (SKL–CUHK) has devoted efforts to improving the yield, quality and stress tolerance of rice and soybean. ‘Homecoming of Soybeans’, a joint project between the SKL–CUHK and Beijing Genomics Institute — Shenzhen (BGI-Shenzhen), has made major breakthroughs in soybean genomic research. The project has decoded the genomes of 17 wild and 14 cultivated soybean accessions and revealed their differences. Wild soybeans have higher genomic diversity than cultivated soybeans. That means wild species have more genetic resources that can facilitate their sustainable cultivation. Due to the depletion of good arable lands and fresh water resources in China, the effective utilization of marginal lands for cultivation has become a high- priority topic. Northern China has many saline lands, and in the country’s hinterland, coastal areas and north western regions, arid lands abound. This makes the development of stress tolerant crops imperative. The soybean is also a nitrogen fixing crop that can absorb nitrogen from the air to fertilize soil at the rate of 100 kg per hectare per year, hence making it an environmentally friendly crop that can rehabilitate degraded lands. The research team of the SKL-CUHK has already identified anti-drought and anti-saline soybean lines and carried out field tests on them in arid regions in Northwestern China and on saline lands in Northern China. With the new genome sequencing data, it is hoped that these soybean lines can be put to greater use. 大豆回家 基因技術除了能應用於醫學外，也是提 升農業生產的利器。由主任辛世文教授 和副主任林漢明教授領導的中大農業 生物技術國家重點實驗室，重點研究 如何提高水稻和大豆的產量、品質和抗 逆性。實驗室與華大基因研究所合作的 「大豆回家」研究項目取得重大突破， 完成十七個野生大豆及十四個栽種大 豆的品種測序，找出了兩者之間的基因 組變化。結果發現，野生大豆在基因的 多樣性方面，遠高於栽種大豆。 這一發現的意義在於，我們可以在野生 大豆內找到很多有利於可持續種植的 基因。在耕地不足，品質不高，淡水資源 亦短缺的中國，環境對作物異常不利， 作物的抗逆性非常值得研究。此外，中 國內陸、東北、沿海的鹽鹼地和西北荒 漠化的土地很多，而大豆的固氮能力很 強，能以每年每公頃一百公斤的效率把 空氣中的氮轉化為有機物質，令土壤肥 沃，修復已退化的土地。 農業生物技術國家重點實驗室的研究 團隊已培養出耐旱和耐鹽的大豆群體， 正在西北乾旱地區和華北鹽鹼地作試 驗，配合最近品種測序的數據，希望能 有更大的應用價值。