^(60)Co-γ辐射对朝天椒种子超微结构、叶表显微结构及分子鉴定的影响

由于朝天椒种质资源多态性低、遗传基础狭窄,加强人工培育朝天椒种质资源尤为重要。为研究^(60)Co-γ辐射对朝天椒的影响,以朝天椒常规品种中农千斤红为试材,对朝天椒干种子进行不同^(60)Co-γ辐射剂量处理(0、25、50、100、200、300、400、500、600 Gy),以无辐射种子为对照,对各处理种子发芽率、成苗率、畸形率、种胚超微结构、叶片显微结构进行测定,并采用SSR分子标记对辐射后长成的幼苗进行分子鉴定。结果表明:辐射剂量小于200 Gy时种子的发芽率、出苗率和成苗率均大于70%;辐射剂量为0、25、50 Gy时辣椒幼苗畸形率均为0%,辐射剂量达100 Gy后畸形率随辐射剂量的增加而增加。对照种子在种胚萌动过程中种胚细胞内线粒体及细胞核等主要细胞器的结构形态均表现正常,^(60)Co-γ辐射剂量为25、200 Gy时种胚内主要细胞器结构和形态仍较为正常,但是随着辐射剂量的增长和辐射时间的增加,种胚细胞的超微结构被损伤的程度愈发严重,线粒体由椭球形膨大成圆球形,脂体变透明,胞质膜、核膜破裂加重,细胞核变形严重,种胚细胞行为异常,直至丧失分裂、代谢功能。经过辐射处理的辣椒种子,长成的幼苗叶片上、下表皮的气孔数与辐射剂量成正相关,表皮细胞的形状也因辐射剂量的增长变得扭曲。经辐射诱变后的长成材料经SSR分子鉴定,较对照发生DNA水平上的变异,扩增谱带突变类型主要为“条带新增型”“混合型”和“条带缺失型”。本试验筛选出了适宜的^(60)Co-γ辐射剂量为200 Gy,以及适宜的引物用于诱变材料SSR分子鉴定,为朝天椒辐射育种提供一定的有益参考。

Preliminary Research on Radiation Breeding of Pteroceltis tatarinowii Maxim.

In order to explore the effect of radiation breeding on new germplasm innovation of Pteroceltis tatarinowii,the dry seeds of P.tatarinowii from Lingyan Temple were used as test materials in this study,which were irradiated by ^(60)Co-γ rays with different radiation doses.The results showed that the emergence rate decreased with the increase of radiation dose,the emergence rate of low dose below 200 Gy decreased slowly,and the emergence rate of high dose above 200 Gy decreased sharply;when the radiation dose ranged from 100 to 200 Gy,the mutagenic effect of P.tatarinowii seeds was the best;and radiation obviously affected the leaf color and leaf shape of seedlings.This study provides original materials for the cultivation of new P.tatarinowii varieties and the study of color-changing mechanism.

^(60)Co-γ辐射诱变在果树育种中的应用与展望

^(60)Co-γ射线是目前辐射诱变育种中最为常见的一种辐射源。综述了^(60)Co-γ射线在果树育种中的应用,包括诱变后的表型、辐射材料、辐射剂量、育种成果、突变体机理研究等,探讨了^(60)Co-γ射线在果树育种中存在的问题,并对^(60)Co-γ辐射技术与杂交育种、植物组织培养、鉴定技术、功能基因组学结合提升育种和分子机制研究效率进行了展望。

^(60)Coγ射线辐射小麦种子对生长发育的影响

以不同剂量的60Coγ射线照射小麦干种子,测定了不同剂量对小麦M1不同生育时期生长发育的影响。结果表明:在150～350Gy范围内,随着剂量的增加,小麦种子的发芽势、发芽率降低,幼根及幼苗生长缓慢,植株高度降低,叶片变短、变窄,抽穗及成熟期推迟。

Effect of irradiation on temperature performance of dispersioncompensation no-core cascade optical-fiber sensor coated with polydimethylsiloxane film

A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.

苎麻不同育种材料辐照诱变效果的比较

用６０Ｃｏγ－射线辐照苎麻的干燥种子、地下茎和试管苗的研究结果表明：对６０Ｃｏγ－射线的辐照敏感性以干种子最低，试管苗最高，地下茎居中，其半致死照射量分别为５．１６，１．２９和２．０６Ｃ／ｋｇ．试管苗的辐照诱变率可达１０％以上，地下茎的辐照诱变率为５％左右，而种子本身变异率虽高，但其辐照诱变率仅３％左右．认为辐射育种与组织培养相结合，可能是苎麻育种的有效新途径．