提高光敏感雄性不育水稻花粉单倍体育种效率及不育花粉植株育性转换特点的研究

Enhance the Efficiency of Haploid Breeding and the Character of Fertility Reversal of Sterile Pollen Plants in Photosensitive Male Sterile Rice

比较了(光敏s/正常品种)F_1及F_2为供体亲本,对在花药培养时所获得的花粉植株中不育个体/全部花粉植株之比例的影响。结果表明,以F_1为供体亲本,在所获得的二倍体花粉植株(A_1)中,不育株(长日下)约占20%左右;而从F_2分离的不育株为供体亲本,相应的比例为90%左右。对获得不育的花粉植株而言,供体亲本经过F_2的选择,在花粉一代中可以提高育种效率3—4倍。指出,以培育光敏感雄性不育系为目的的花药培养,与一般育种之花药培养采用杂种F_1为供体亲本不同,不仅应对杂种F_2代在长日照条件下进行不育株的选择,而且应在短日照下对这种不育株作育性转换的双重选择。以这种个体作为花药培养的供体亲本,可以大大提高育种效率。 在长日照下表现不育的花粉植株的育性转换具多样性。来自同一组合的不育花粉植株在晚造(短日照)条件下,其花粉有的染色,频率高且稳定;有的虽然可变为染色,但频率不高或不稳定或二者兼有;有些却一直不为Ⅰ-KⅠ染色,或即使染色频率也在10%以下。这一结果与收集全国各地15个光敏核不育系在本昕同期种值条件下的反应十分吻合。这说明通过花药培养,从特定的组合培育出所需要的光敏/光温互作或温敏型的核不育系的可能性是存在的。

The effect of different generation (F1 and F2) in the combination which was photosensitive male sterile (P-ms) crossed a normal rice, as the donor plants used for anther culture on the ratio of male sterile pollen plant (MSPP) to the total pollen plant (TPP) was studied. The result showed that if F1 was used as the donor plant for anther culture, in long day condition, the frequency of MSPPs making up to the TPPs was around 20%. But the corresponding frequency from F1 as the donor plants was around 90%. The efficiency of 3-4 fold for MSPP was raised if male sterile plant segregated in F2 were selected and used as the donor plants for anther culture. The authors point out that double selections should be undertaken in F, generation if the breeding goal is to develop a new photosensitive ms line. One is 10 select ms plants segregated from F2 generation in long-day condition (LDC) and the other is to select the individual which could be well tuned into fertility from male sterile in short day condition (SDC). In other words, the plants selected as the donor plants in F2 generation should be male sterile in LDC and fertile in SDC.The result in this experiment showed that the fertile reversal of MSPPs under same combination was different. According to the expressions of fertile reversal of MSPP in SDC, they could be divided into three groups. 1) Sterility of the MSPPs in this group could be reversed fertile. The pollen grains of MSPP could be stained by I-KI solution during September and October in Guangzhou and 'he frequency of staining pollens were higher and stable, and the plants in this group possessed the charicters of photosensitive male sterile rice. 2) The frequency of staining pollens of the MSPPs in this group was low and unstable or the date of fertility reversal was very late (after October), and they had the characters of photo-thermo interactonal sensitive male sterile rice. 3) The fertility reversal of MSPPs in this group was not observed during the whole stage of SDC. The frequency of staining pollen was zero or less than 10%, they showed the characters of thermosensitive male sterile rice. Jt is worth, to note that this result is completely in correspondence with the one from the expressions of the 15 P-ms lines collected from the whole country. It is concluded that a photo-,thermo- or photo/thermo-interactive sensitive male sterile line might be bred by anther culture method from a specific hybrid combination (P-ms rice/normal variety rice).