马铃薯单细胞60Co-γ辐射诱变的初步研究

采用60Co-γ辐射处理马铃薯单细胞,快速高效获得马铃薯突变体材料,为丰富马铃薯育种材料提供支持。以紫色马铃薯‘黑美人’试管苗和块茎2种外植体为材料,进行愈伤组织诱导和继代培养并建立细胞悬浮培养系。以紫色马铃薯‘黑美人’单细胞为辐射材料,采用5个剂量的60Co-γ射线辐射处理,观察比较不同辐射处理条件下单细胞的再生率。结果表明：经过10 Gy的60Co-γ辐射处理后,有一定数量的再生植株产生,20 Gy的60Co-γ辐射处理后,植株再生慢,再生率低。经过40Gy、60 Gy的60Co-γ辐射处理后无再生植株。细胞核制片观察结果表明：通过30天的再生培养后,细胞核的外形有明显的变化,10 Gy的辐射处理对细胞核的影响仍明显低于20 Gy,说明60Co-γ辐射处理单细胞引起的诱变具有一定的稳定性,有望获得到马铃薯突变体材料。     

HL-60 Cells Apoptosis Induced by Low-dose Cytosinearabinoside in Vitro

Cytosinearabinoside(Ara-C) is an important agent used for treatment of leukemia, but its mechanism of action at low dose is not clear, maybe is related to its effectson differentiationor apoptosis of cells. The authors investigate The relationship between bcl-2, p53 expression and apoptosis of HL-60 cells induced by low-dose cytosinearabinoside (10~(-8)M) by means of TUNEL method, flow cytometry, immunohistochemistry and in situ hybridization. The results show that low-doseAra-C could inhibit cell growth and induce apoptosis, and the effects might be related to increase of P53protein and decrease of bcl-2 mRNA expression.     

60Coγ射线种子辐射对大花高代 组培苗的生长及诱变效应

以0Gy、10Gy、50Gy、100Gy、150Gy和200Gy不同剂量的60Coγ射线辐射种子，研究其对大花高代组培苗生长影响的结果表明，在50~200Gy范围内，根和真叶的生长以及植株高度都不同程度地受到了抑制，且抑制程度与辐射剂量呈正相关，而10Gy则能促进根和真叶的生长。随着剂量的增高，死亡率增高，组培苗生长41d时的半致死剂量(LD50)为150Gy。各处理组培苗培养70d后，少量瓶内开花，出现花型、花色和花瓣变异。花型变异主要由对照的正常花形变为蝴蝶形。花色变异主要是颜色变浅，甚至变为白色。花瓣变异可由原来的单瓣变为重瓣花。以上结果表明，60Coγ射线辐射可以提高突变频率且诱变效应明显，有利于在大花高代育种中产生色彩丰富，花型、株型美观的变异类型     

12C6+离子束辐照糜子诱变突变群体的构建与SSR分析

为构建物理诱变糜子突变体库,采用50、100、150、200和250 Gy剂量碳离子束(12C6+)辐照陇糜7号和晋黍9号种子,结合混合系谱法和系统聚类分别构建2个含52和79个株系的M5寡表型突变群体。田间试验结果显示,诱变M1出苗率随剂量增大明显降低,陇糜7号M1半致死剂量为150 Gy,晋黍9号M1半致死剂量为100 Gy,且100、150 Gy诱变下M4变异最多。不同诱变剂量下M5、M6表型稳定且株高、产量性状、成株色及粒色均表现出明显遗传差异。从2个M6群体中分别选择9和11个代表性株系,利用多态性SSR引物进行分子验证,与亲本相比,6对SSR引物在陇糜7号的9个株系中位点变异基因型数为1~2,在晋黍9号的11个株系中位点变异基因型数为1~4,突变群体存在丰富的遗传多样性。     

Vitamin C in broccoli (Brassica oleracea L. var. italica) flower buds as affected by postharvest light,UV-B irradiation and temperature

In this study, the changes in vitamin C, l-ascorbic acid (AA) and l-dehydroascorbic acid (DHA) levels in broccoli flower buds were examined during pre-storage and storage periods, simulating refrigerated transport with wholesale distribution and retail, respectively. Broccoli heads were pre-stored for 4 or 7 days at 0 °C or 4 °C in the dark and then stored for 3 days at 10 °C or 18 °C. During storage the broccoli heads were exposed for 12 h per day to three different levels of visible light (13, 19 or 25 μmol m⁻² s⁻¹) or a combination of visible light (19 μmol m⁻² s⁻¹) and UV-B irradiation (20 kJ m⁻² d⁻¹), or they were stored in the dark. The vitamin C content in broccoli flower buds during storage was significantly affected by pre-storage period and temperature. Higher vitamin C levels in flower buds after storage were observed for broccoli heads pre-stored for 4 days or at 0 °C as compared to those pre-stored for 7 days or at 4 °C. Storage temperature also affected vitamin C in broccoli flower buds, with higher levels observed for broccoli stored at 10 °C than at 18 °C. Hence, vitamin C in broccoli flower buds was demonstrated to decrease together with increasing pre-storage period, pre-storage temperature and storage temperature. AA in broccoli flower buds was influenced mainly by storage temperature and to a minor extent by pre-storage temperature. The DHA level and DHA/AA ratio were stable in flower buds of broccoli pre-stored for 7 days, whereas increasing tendencies for both DHA level and ratio were observed after pre-storage for 4 days. These results indicate a shift in the ascorbate metabolism in broccoli flower buds during storage at low temperatures, with its higher rate observed for broccoli pre-stored for shorter time. There were no effects of the light and UV-B irradiation treatments on vitamin C, AA and DHA levels in broccoli flower buds.     

^60Co—γ射线诱发的籼型温敏核不育水稻叶色突变系变异分析

＾６０Ｃｏ－γ射线诱发的８个灿温敏核不育系水稻叶色突变系可分为三种类型,即叶色突变高温表达型、低温表达型及温钝型。     

低浓度玉米小斑病菌C小种毒素培养滤液诱导寄主抗性的研究

利用低浓度玉米小斑病菌C小种毒素培养滤液作为激发子诱导玉米获得抗病性。以一对同核异质玉米B37自交系为试材,采用离体叶片接种法检测适宜诱导抗性的低浓度玉米小斑病菌C小种毒素培养滤液作为激发子诱导玉米抗病性的适宜诱导浓度,测定与抗病性相关酶的变化。经用1∶50和1∶60的低浓度玉米小斑病菌C小种毒素培养滤液预处理植株,再接种高浓度(1∶10)毒素培养滤液处理的病斑面积分别为(0.30±0.14)和(0.36±0.17)mm2,而对照为(2.70±0.24)mm2,是处理的7.5~9倍,差异极显著。经0~72 h的动态检测,以1∶60预处理效果为最佳,与对照相比,苯丙氨酸解氨酶(PAL)活性平均提高了23.4%,过氧化物酶(POD)活性平均提高了65.9%,有害物质丙二醛(MDA)的含量平均降低了28.2%。叶片内部所产生的生化反应与叶片表面的抗性病理反应相吻合,证实低浓度玉米小斑病菌C小种毒素滤液本身能够成功地作为激发子来诱导寄主-玉米获得抗性。