- 作者: Kenneth J. Frey
- 作者服務機構: Department of Agronomy Iowa State University
- 中文摘要: 30年來,燕麥育種家一直知道在改良栽培種燕麥上,野生種燕麥A. sterilis是一個提供優良基因的主要種源,但在1960年代這個野生種只被用為抗病基因的來源而已。例如它帶有的抗冠銹病(crown rust)和BYD的基因,這些抗病基因已被利用了10至20年之久。到了1970年代,雖由A. sterilis所提供的基因使得在燕麥育種計畫中產生的品系其穀粒含有20-22%的蛋白質含量,但是沒有一個品系被直接命名推廣成為一個栽培品種。而在過去15年當中,它們卻成為提昇燕麥穀粒蛋白質含量的一個重要親源。1970年代後期所開始的高油分含量的燕麥育種的研究上,也沒有一個高含油分的品系被推廣栽植,但是在有關的育種計畫中已經發現若干品系含油分超過一般品系的50%。兩個高產的栽培品種Hami-lton和Sheldon,它們具有A. sterilis的細胞質和若干A. sterilis的核基因。A. sterilis也是Starter栽培品種的親本之一。 燕麥是一個典型的只具有狹窄的基因庫的禾穀類作物。從其他多元體的燕麥物種轉移有用的基因,基本上仍然受到若干限制。然而栽培種燕麥的祖先,亦即6元體的野生種燕麥A. sterilis已被證明它可以擴大栽培種燕麥的基因庫。它對下列燕麥的性狀改良,有其一定的貢獻:對冠銹病、稈銹病的抗性,對BYD的耐病性及露菌病的抗性,對種實蛋白質及油分的含量提高,植株的生長活力等。因為由A. sterilis引入的基因與栽培種(A. satiaa)的基因庫內的基因有相當的歧異性及互補性,而在A. sterilis本身的這個物種中,如葉、穗等性狀,光週期及對溫度的反應及B-qlucan含量等,都具有相當的遺傳變異,因此可能只因為A. sterilis所提供的基因,使得燕麥迄今仍是人類栽培的一個作物。
- 英文摘要: The value of A. sterilis as a source of new desirable genes for improving cultivated oats was rec-ognized about 3 decades ago, but during the 1960s, this species was used only as a donor of disease resistancealleles. And resistance to crown rust and BYD from A. sterilis have been in use in farmers' fields for 1-2decades. In the 1970s, experimental oat lines with 20-22% groat protein resulting from alleles from A.sterilis were developed. None of these was released as a cultivar directly, but their use as parents almostassuredly has been a factor in the general elevation of groat protein content in the past 15 years. Theresearch on breeding high-oil oats, begun in the late 1970s, has not yet brought release of a cultivar withhigh groat-oil content to fruition, but experimental lines from this program have 50% higher groat-oilcontent than ever found in either species. Hamilton and Sheldon oat cultivars, both very high yielding,have A sterilis cytoplasm and an unknown proportion of nuclear genes from A. sterilis. Starter cultivarhas A. sterilis in its parentage. Oats represent a classic example of a crop species with a demonstrated narrow gene pool. Intro-gression of useful genes from Avena spp of other ploidy levels has proven of very limited value. However,A .sterilis, the hexaploid progenitor of cultivated oats, has proven to be a virtual treasury of genes forbroadening the cultivated oat gene pool. For every trait that has been studied-crown- and stem-rust re-sistance, BYD tolerance, mildew resistance, protein and oil concentration in the grain, vigor traits-A. sterilishas contributed useful genes for enhancing the traits. The alleles contributed from A. sterilis are diversefrom and complementary to those alleles present in the A. sativa gene pool. And studies conducted onA. sterilis itself indicate that immense genetic variability exists in this species for other traits as well; e.g.,leaf and panicle characteristics, photoperiod and vernalization responses, B-glucan content, etc. Oats maysurvive as a crop only because of the genes introgressed from A. sterilis.
- 中文關鍵字: oat; Avena; gene pool; resistance; grain composition; prebreeding.
- 英文關鍵字: --