Use of nitrate non‐utilizing (nit) mutants to determine phenological stages at which Botrytis cinerea infects wine grapes causing botrytis bunch rot

Botrytis bunch rot (BBR), caused by Botrytis cinerea, degrades wine grapes during ripening, even though infection can occur as early as flowering. Effective BBR management requires knowledge of whether some stages of fruit development are more important than others in relation to infection and BBR severity at harvest. Bunches of Vitis vinifera ‘Sauvignon blanc’ and/or ‘Pinot noir’ were inoculated in two vineyard trials and one glasshouse trial with nitrate non‐utilizing (nit) mutant strains at three phenological stages: early flowering, pre‐bunch closure (PBC) and veraison. Isolates recovered from symptomless berries at veraison and from bunches with symptoms at harvest were screened to measure the incidence of the nit strains used in the inoculations. It was found that latent infections, which resulted in BBR at harvest, could become established at all three phenological stages and no single stage was associated with greater latent incidence or harvest severity than any other stage. It was concluded that a proportion of BBR at harvest resulted from the expression of latent infections that had accumulated throughout the season. However, the time between infection and BBR symptom expression in near‐ripe grape berries was sufficiently short for polycyclic secondary infection to also contribute to epidemic development.     

Application of citric acid and mild heat shock to minimally processed sliced radish: Color evaluation

The aim of this research was to study the effects of two hurdle technologies, citric acid application (CA) at 0.3%, 0.6% and 0.9% and thermal treatments (IT) for 1, 2 and 3 min at 50 °C, on the color of radish slices over 10 d of refrigerated storage. Contribution of the hurdles and their interactions were evaluated by examining the treatment effects on the following parameters: chromatic coordinates (L*, a* and b*) and the indices: chroma (ΔC*), total color difference (ΔE) and Color Index (CI*).The chromatic parameters for fresh radish (control samples) were L₀ = 69.43 ± 0.62, a₀ = −0.46 ± 0.05 and b₀ = 5.37 ± 0.37, while the calculated color indices were chroma = 5.39 ± 0.36, ΔE = 0 and CI* = −1.19 ± 0.17. Regarding control samples, the b* values showed an increasing trend during storage, which was associated with browning of the slices. Both ΔE and ΔC* values presented similar trends as reported for b*. Based on statistical analysis of the parameters and indices tested, the single hurdle application of low citric acid concentration (0.3%) or intermediate immersion time (2 min) at 50 °C minimized the radish slices color changes during storage. However, better results were obtained when two hurdles in series were applied. According to analysis, the treatment T7 (1 min IT, 0.3% CA) was selected as the best treatment to improve the retention of typical natural color of the minimally processed sliced radishes.     

国外彩色甜椒成熟果实颜色遗传研究进展

综述了近年来国外在彩色甜椒成熟果实颜色遗传及分子生物学方面取得的研究成果与进展,阐明了利用彩色甜椒成熟果实颜色遗传模型及分子标记技术进行不同果色甜椒新品种选育的方法.     

利用制霉菌素抗性筛选赤霉素高产菌株的研究

利用紫外、亚硝基胍以及复合诱变的方法,采用制霉菌素抗性筛选,选育赤霉素高产突变株.在磁力搅拌下,菌悬液先后经过浓度为3.0 mg/mL亚硝基胍30 min和紫外线(30 W,20 cm距离)45 s诱变,得到抗制霉菌素的赤霉菌突变株.进一步摇瓶复筛,获得赤霉素高产菌株,其中菌株ZNL-1产赤霉素效价达到2 170 μg/mL,较之诱变前发酵效价平均提高了16.7％.经10次斜面传代,菌株ZNL-1产素水平稳定,菌株遗传稳定性较好.表明,赤霉菌抗制霉菌素的抗性与赤霉素高产之间存在对应关系.     

基于数码摄像的蓝藻识别研究及工程实现

针对近年来我国内陆水体富营养化程度日益严重,导致蓝藻水华大规模爆发的情况,为了简单快速识别蓝藻,结合当前数码摄像技术不断提高的实际,提出并实现了利用高分辨率、高质量的图片对蓝藻的关键特征进行识别的方法。该方法从空间域和频域这两个领域对蓝藻图片进行分析,首先引入色彩空间原理,根据预先所设的蓝藻特征值门限处理图片,提取蓝藻在空间域上的颜色特征;然后利用傅里叶变换把空间域信号变换到频域,并通过带通滤波及高通滤波技术分析蓝藻图片,得到蓝藻在频域上的纹理特征;最后结合这两个不同领域各自的结果交叉识别图片中的蓝藻。试验结果表明,该方法能够正确得到蓝藻图片的颜色特征和纹理特征,通过两个特征能很好地识别蓝藻,取得了较好的效果。     

马铃薯晚疫病菌对氟吡菌胺抗性突变体的获得及其生物学性状

【目的】研究抗氟吡菌胺突变体对不同杀菌剂的交互抗性并评估马铃薯晚疫病菌对氟吡菌胺的抗性风险。【方法】通过紫外线照射菌丝体、紫外线照射孢子囊和药剂驯化的方法获得抗氟吡菌胺的马铃薯晚疫病菌突变体,计算突变体的突变频率,测定抗性突变体的抗性水平,研究突变体在无药条件下继代培养10代后抗性能否稳定遗传,测定突变体在RSA培养基和离体叶片上的适合度(菌丝生长速率、产孢子囊能力及复合适合度指数),比较抗性菌株与其亲本敏感菌株的竞争力,分析对氟吡菌胺表现不同敏感性的菌株对不同药剂的交互抗性,并通过笔者实验室建立的抗性风险量化标准评定马铃薯晚疫病菌对氟吡菌胺的抗性风险。【结果】共获得21个抗性菌株,抗性水平介于61—3 157倍,紫外线诱导孢子囊的突变率为2.78×10~(-7);大多数抗性突变体的适合度与其亲本菌株无显著性差异;竞争力测定试验中,2株突变体的第1、3、7代的共18次抗药频率测定中,有3次测定的抗药频率显著低于初始频率,有4次测定的抗药频率显著高于初始频率,其余11次测定的抗药频率与初始频率均无显著性差异;所有突变菌株的抗药性均能稳定遗传;抗氟吡菌胺菌株及其亲本菌株对氟吡菌胺的lgEC_(50)与这些菌株对嘧菌酯、吡唑醚菌酯、霜脲氰、烯酰吗啉、双炔酰菌胺、甲霜灵、氟醚菌酰胺的lgEC_(50)之间的相关系数(r)分别为0.104(P=0.654)、0.311(P=0.170)、0.228(P=0.081)、0.376(P=0.093)、0.214(P=0.351)、0.122(P=0.599)、0.963(P=0.000);致病疫霉对氟吡菌胺基本抗性风险值为15。【结论】氟吡菌胺与氟醚菌酰胺之间存在交互抗性,与嘧菌酯、吡唑醚菌酯、霜脲氰、烯酰吗啉、双炔酰菌胺、甲霜灵之间无交互抗性,马铃薯晚疫病菌对氟吡菌胺的固有抗性风险为高度,应加强马铃薯晚疫病菌对氟吡菌胺的抗性风险管理,建议生产上将氟吡菌胺与其他类药剂交替或混合使用。     

北美糖槭单板染色工艺的优化

考查了染色温度、染液质量分数、促染剂用量、染色时间、固色剂用量、固色时间、V(单板)∶V(染液)7个因素对北美糖槭单板上染率和色差的影响,通过直观和方差分析得出了影响单板上染率和色差的显著因素及最佳染色工艺方案。在此基础上,采用模糊数学综合评判法对上染率和色差2个评价指标进行了综合评判。结果表明:染液质量分数和染色温度对上染率和色差影响显著;基于模糊数学综合评判得出的最优染色工艺参数为染色温度50~55℃、染液质量分数3.0%、促染剂用量40 g/L、染色时间3.0 h、固色剂用量15 g/L、固色时间75 min、V(单板)∶V(染液)=1∶40。     

Antibrowning of the Adductor Muscles of Bay Scallop by Glutathione During Hot Air Drying

ABSTRACT

Browning in the adductor muscle of bay scallop (Argopecten irradians) tends to occur during hot air drying due to polyphenoloxidase (PPO) and Maillard reaction and decreases the sensory quality and commercial value of bay scallop adductor muscles (BSAM). In the present study, the effects of glutathione on the browning inhibition of BSAM were evaluated. The PPO activity in BSAM was inhibited by 97.8 with 0.08% glutathione. The browning of BSAM pretreated with glutathione was evaluated during hot air drying. Compared with the control, BSAM pretreated with glutathione resulted in less drying time and browning during hot air drying. The results indicate that pretreatment with glutathione may be a promising method of BSAM browning inhibition during hot air drying.     

热烫温度和时间对魔芋片干燥动力学和品质的影响（摘选）

该文对热风干燥魔芋片的制备工艺条件进行了优化。研究了热烫时间（0、1、3和5 min）、热烫温度（80和90 ℃）和干燥温度（70、80和90 ℃）对魔芋片干燥动力学及品质特性（色泽、质地、褐变和感官品质）的影响。结果表明,完全干燥发生在降速期间。较长的热烫时间和较低的干燥温度能够起到较好的护色作用,降低魔芋片的褐变指数。热烫同时可以降低产品的硬度和破裂度。在90 ℃情况下热烫3 min,然后在80 ℃下干燥480 min可以使最终产品具有最佳品质。      

水稻类病斑突变体spl31的遗传分析与基因定位

利用EMS诱变水稻籼型恢复系缙恢10号, 从其后代中鉴定出一个类病斑突变体spl31, 该突变体三叶期以前表型正常, 四叶期后叶片陆续出现黄色斑点, 随着植株的生长, 面积逐渐扩大成边缘黄褐色的病斑, 至成熟时病斑相互连接成片, 导致叶片坏死。透射电镜结果显示突变体细胞的叶绿体基粒片层堆叠不规则。组织化学分析显示突变体细胞被染成深蓝色, 呈离散状分布, 说明spl31病斑是自发形成的。光合数据显示spl31基因突变对病斑叶片正常部位细胞的光系统II影响较小。农艺性状分析发现突变体千粒重下降、结实率降低。遗传分析表明, spl31的突变性状由1对隐性核基因控制, 该基因被定位于水稻第12染色体着丝粒附近, 引物ID104和ID11之间, 物理距离为383 kb, 并与标记ID105共分离。