-
如图1所示,碳离子束辐照后油葵种子出苗率和幼苗存活率变化趋势一致,随着辐照剂量的增加呈下降趋势。辐照剂量在0~80 Gy之间,出苗率和存活率急剧下降,与对照相比,80 Gy辐照出苗率下降55.68%,存活率下降64.66%;辐照剂量80~160 Gy之间出苗率和存活率降低较为平缓,与80 Gy相比,160 Gy辐照出苗率下降20%,存活率降低18.71%。表明碳离子束辐照对油葵的出苗率和存活率抑制作用具有明显的剂量效应。根据回归方程计算得出油葵存活率半致死剂量(LD50)为55 Gy。
-
如图2所示,0, 20, 40, 60, 80, 100, 120, 160 Gy的碳离子束辐照后花粉活力均值分别为92.01%, 92.83%, 88.28%, 90.54%, 78.55%, 79.61%, 60.95%, 47.59%,碳离子束辐照抑制了花粉活力。花粉活力变化范围分别为82.91%~97.59%, 58.14%~97.69%, 50.63%~97.65%, 43.75%~98.22%, 36.13%~98.69%, 33.96%~96.26%, 26.25%~96.94%, 16.37%~96.39%。对照组的花粉活力分布较为集中,随着辐照剂量增加,花粉活力分布逐步下移,碳离子束对花粉活力的抑制作用逐渐增大。对照组上下四分位数差异较小,组内变异幅度较小。较低剂量(20~60 Gy)下,花粉活力与对照组差异不显著,但是低活力的花粉数量逐渐增加;高剂量(80~160 Gy)辐照显著降低了花粉活力(P<0.05),上下四分位数差异也逐渐增大,碳离子束辐照增加了花粉活力变异幅度。
-
将柱头可授性分为不具有可授性、具有较弱可授性、具有较强可授性三个等级。如图3所示,随着辐照剂量增加,较强可授性柱头的百分比逐渐减低,从0 Gy的78%降低为160 Gy的25%;较弱可授性和无可授性柱头的百分比逐渐增加。较弱可授性的柱头百分比从0 Gy的19%增加为160 Gy的50%;不具有可授性柱头的百分比从0 Gy的3%,增加为160 Gy的25%。表明碳离子束辐照降低了油葵柱头的可授性。
-
油葵是异花授粉作物,自交结实率较低,在生产上主要在自然条件下通过昆虫进行授粉杂交,而在亲本材料选育过程中则需要通过自花授粉选择纯合的自交系。本文测定了自然授粉条件下的混交结实率和自花传粉条件下的自交结实率。如图4所示,混交结实率显著高于自交结实率(P<0.05)。碳离子束辐照后,混交结实率和自交结实率变化趋势一致,即随着辐照剂量的增加,混交结实率和自交结实率分别与辐照剂量呈线性关系逐渐下降。与对照相比,40~160 Gy的碳离子束辐照显著降低了油葵混交结实率(P<0.05),20~160 Gy的碳离子束辐照显著降低了油葵自交结实率(P<0.05)。根据回归方程计算得出混交结实率的半不育剂量(SD50)为153 Gy,自交结实率的半不育剂量(SD50)为84 Gy。
为了探究雄蕊在碳离子束诱导结实率降低中的作用,用辐照植株的花粉给未辐照植株的柱头授粉,测定油葵异交结实率。结果显示(见图5),辐照花粉×未辐照柱头的异交结实率随着碳离子束辐照剂量增加而逐渐下降,与对照相比,80~160 Gy碳离子束辐照显著降低辐照花粉×未辐照柱头的异交结实率(P<0.05)。为了探究雌蕊在碳离子束诱导结实率降低中的作用,用未辐照植株花粉给辐照植株的柱头进行授粉,测定油葵异交结实率。结果(图5)显示,辐照柱头×未辐照花粉的异交结实率随着碳离子束辐照剂量增加而逐渐下降,与对照相比,20~160 Gy碳离子束辐照显著降低辐照柱头×未辐照花粉的异花授粉结实率(P<0.05)。
-
为验证碳离子束辐照处理下花粉活力、柱头可授性对结实率的影响,进行了相关性分析。如表1所列,碳离子束辐照处理下,花粉活力与自交结实率成显著正相关(P<0.05)、与混交结实率、辐照花粉×未辐照柱头异交结实率成极显著正相关(P<0.01),相关系数在0.831 1~0.985 5之间。如表2所列,碳离子束辐照处理下,较强可授性柱头的百分比与自交结实率、混交结实率、辐照柱头×未辐照花粉异交结实率呈显著正相关(P<0.05),相关系数在0.824 1~0.831 4之间。如表3所列,碳离子束辐照处理下,不具有可授性柱头的百分比与自交结实率、混交结实率、辐照柱头×未辐照花粉异交结实率成显著负相关(P<0.05),相关系数在−0.861~−0.812之间。
结实率 方程 r 显著性 自交 y=0.853x−33.19 0.831 1 * 混交 y=0.799x−0.454 0.900 8 ** 辐照花粉×未辐照柱头 y=1.302x−30.47 0.985 5 ** 注:*表示显著性差异P<0.05,**P<0.01。 结实率 方程 r 显著性 自交 y=0.840x−17.610 0.824 1 * 混交 y=0.728x+17.796 0.825 7 * 辐照柱头×未辐照花粉 y=0.823x−1.608 0.831 4 * 注:*表示显著性差异P<0.05。 结实率 方程 r 显著性 自交 y= −1.870x+51.844 −0.812 * 混交 y= −1.715x+78.855 −0.861 * 辐照柱头×未辐照花粉 y= −1.865x+66.744 −0.834 * 注:*表示显著性差异P<0.05。
Effects of Carbon Ion Beam Irradiation on the Fruiting Characters of M1 Oil Sunflower
doi: 10.11804/NuclPhysRev.40.2022030
- Received Date: 2022-03-11
- Rev Recd Date: 2022-04-29
- Publish Date: 2023-03-20
-
Key words:
- carbon ion beam irradiation /
- oil sunflower /
- seed setting rate /
- pollen viability /
- stigma receptivity
Abstract: The dry seeds of oil sunflower were irradiated with the carbon ion beam provided by the Heavy Ion Research Facility(HIRFL) in Lanzhou. To research the effects of carbon ion beam irradiation on the fruiting characters of M1 oil-sunflower, the seedling emergence rate, survival rate, pollen viability, stigma receptivity and seed setting rate under different pollination conditions were measured. The results showed that the seedling emergence rate, survival rate, pollen viability and seed setting rate reduced with the irradiation dose increasing. Compared with control, the emergence rate and survival rate of oil-sunflower decreased by 55.68% and 64.66% after seeds irradiated with a carbon ion dose of 80 Gy. This study also revealed that seeds were irradiated with 20~160 Gy showed very low self-cross seed setting rate, and the mixed-cross seed setting rate were significantly reduced at irradiation of 40~160 Gy. Pollen viability decreased from 92.01% of the CK to 47.59% of the 160 Gy irradiation. With the irradiation dose increasing, the percentage of stigmas with higher receptivity reduced, and the percentage of stigmas with lower receptivity and no receptivity increased. All results indicated that the damage of carbon ion beam irradiation inhibited the fertility of flower organs and reduced the seeding rate. According to the semi-lethal dose of survival rate and the semi-sterile dose of mixed-cross seed setting rate, the recommended irradiation dose range of oil sunflower is 55 to 153 Gy. Our findings may lead to more reference for the selection of suitable irradiation dose for oil sunflower breeding by carbon ion beam irradiation.
Citation: | Xiaofeng CHEN, Libin ZHOU, Wenjie JIN, Zhuanzi WANG, Wenliao ZHANG, Wenjian LI, Yunling PENG, Ying QU, Ping MU. Effects of Carbon Ion Beam Irradiation on the Fruiting Characters of M1 Oil Sunflower[J]. Nuclear Physics Review, 2023, 40(1): 106-112. doi: 10.11804/NuclPhysRev.40.2022030 |