抗真菌转基因水稻生态适合度评价

在田间自然条件下,通过两年两季单独种植(非竞争)和混合种植(竞争)试验,分析比较抗真菌转基因水稻E121-2-1和E122-2-9与其非转基因受体亲本E32和常规稻粤香占在农艺性状、繁殖能力、花粉活力、种子活力、种子库持久力和自生性等适合度成分上的差异,评价抗真菌转基因水稻的生态适合度。结果表明,在竞争情形下,E121-2-1和E122-2-9的株高、千粒重和每穗总粒数在两年均显著降低或在其中一年显著降低,E121-2-1和E122-2-9农艺性状的竞争能力总体上低于E32和粤香占。E121-2-1和E122-2-9的净替代率在竞争态势下两年均呈下降趋势,其中E121-2-1在其中一年下降显著,而E32和粤香占的净替代率随不同年份升高或下降,但变化不显著。E121-2-1和E122-2-9的花粉萌发率、种子发芽势两年均显著低于E32和粤香占,种子发芽率和田间自生苗率在其中一年显著低于E32和粤香占,种子库持久力与E32和粤香占相比两年均无显著差异。只有E121-2-1和E122-2-9种子的休眠期两年均显著高于对照E32和粤香占。结果说明转四价抗真菌基因水稻E121-2-1和E122-2-9的生态适合度优势不强,其种群在自然界中的生存竞争和延续能力不会超越非转基因水稻。

Assessment on the ecological fitness of anti-fungal transgenic rice

In order to assess the ecological fitness of anti-fungal transgenic rice lines, E121-2-1 and E122-2-9, their fitness component-related traits such as agronomic traits, reproductive capability, pollen viability, seed viability, seed bank persistence and volunteer possibility were analysed by comparison to those of the untransformed counterparts E32 and the conventional variety Yuexiangzhan during all of them were grown under a natural paddy field for two different cropping seasons of two consecutive years, according to the design of non-competition (monocultures) and competition (E121-2-1 or E122-2-9 mixtures with E32 and Yuexiangzhan) respectively. The results showed that the plant height, 1000-grain weight and number of spikelets per panicle of E121-2-1 and E122-2-9 under competitions were significantly lower than those under non-competitions in two years or one of two years, the competitiveness of agronomic traits of E121-2-1 and E122-2-9 were substantially inferior to that of E32 and Yuexiangzhan. The net replacement rates of E121-2-1 and E122-2-9 under competitions were decreased in two years, especially that of E121-2-1 decreased significantly in one of two years, but no significant differences were observed for the net replacement rates of E32 and Yuexiangzhan between competitions and non-competitions even though their net replacement rates increased or decreased according to different years. In contrast to E32 and Yuexiangzhan, E121-2-1 and E122-2-9 were statistically with lower rates of pollen germination, seed germinating energy, seed germination and volunteer in two years or one of two years, with longer periods of seed dormancy and with approximative abilities of seed bank persistence in two years. It was concluded that E121-2-1 and E122-2-9 had no advantages in ecological fitness, and they would not exceed their non-transgenic counterparts in survivability and sustainability of population under a natural conditions.