"神舟"三号飞船搭载对草地早熟禾生物学特性的影响

利用“神舟”三号(SZ-3)飞船搭载草地早熟禾Poa pratensis cv．Nassu干种子作为处理，未搭栽种子作为对照。分别观察了发芽率及播种80d后植株的叶片数、分蘖数、叶片宽及株高等指标。结果表明，空间条件对草地早熟禾发芽率没有明显影响；但是经过空间搭载后的植株平均叶片数增加了6片，并出现了叶片数81片的变异植株(对照植株叶片数最多为21片)；平均叶片宽增加到2．43mm(对照为1．96mm)，其中17．8％的植株叶片宽超过3．3mm(对照植株叶片宽均小于3．2mm)，最宽达5．5mm；株高变异范围为3～155mm(对照为9～108mm)；分蘖数最多达到26个(对照最多为5个分蘖)。综合分析各生长指标的变化，可获得至少2种不同有益变异类型植株：1)植株明显矮化，可有效减少生长季内刈割次数，降低管理养护成本；2)生长速度快，分蘖增多，叶片数明显增加，可有效缩短成坪期。这些变异类型在生产应用和遗传育种方面均具有一定的价值。

Changes in biological characteristics of Poa pratensis carried by Shenzhou-3 spaceship

Dry seeds of Poa pratensis Nasu were carried by SZ-3 spaceship (treatment) and compared with seeds on the earth (CK). For the seeds, characteristics including germination rate, and leaf number, tiller number, leaf width, and plant height 80 days after sowing were determined. The treatment showed 6 more leaves than CK, and a mutation with 81 leaves appeared (CK had only 21 leaves maximum). For the control, tiller number ranged from 0 to 5 but was 0 to 26 for the treatment. Leaf width increased from 1.96 mm for the CK to 2.43 mm for the treatment; and 17.8% of plants in the treatment had widths of 3.3 to 5.5 mm, but CK plants averaged less than 3.2 mm. Plant height was 9 to 108 mm for the CK but 3 to 155 mm for the treatment. We can see at least two different beneficial types of mutated plants by summarizing the changes in growth norms. One is that of plants dwarfing, which can reduce the number of mowing times in the growing season, and reduce the cost of management and maintenance. The other one is plants with fast growth and higher tiller and leaf number, which can shorten lawn establishment time. These mutation types are valuable for production application and breeding.