摘 要：
南京及华东地区的油菜与十字花科蔬菜普遍发生花叶病。病原病毒經抗性(失毒温度、稀释終点、体外保毒期)測定和寄主反应測定,认为可以分作三大类型:分别为芸苔病毒2号,黄瓜病毒1号与烟病毒1号的株系。前两种病毒都能为害油菜、大白菜、白菜、芥菜、蘿卜等,但不为害甘蓝型的蔬菜,并都能引起菠菜和茼蒿的花叶,和在烟上引起局部枯斑。第一型在烟农特400号和心叶烟上不引起花叶,而第二型在烟和心叶烟上都能引起系統性花叶。第一型不为害心叶烟,而第三型可在心叶烟上引起小枯斑。第一型与凌立、楊演的油菜花叶病毒相近似,而和范怀忠、柯冲从十字花科蔬菜中所分离出的分离物1号最为相象。与裘維蕃、王祁楷在白菜上所发現的孤丁病毒的差别,在于不能侵害甘蓝类的蔬菜。第二型病毒与范怀忠、柯冲的分离物3号相近似,但与典型的黃瓜花叶病毒仍具有一定的差异。这些病毒在油菜上所引起的症状却沒有明显的差別。1、2两个类型的病毒都有一部分能为害早生朝鮮型的油菜,引起系統性黄斑及枮斑,病重的也能早期死亡。大田中的油菜病株的病毒,大多属于第一型病毒。病毒主要由桃蚜和蘿卜蚜传染,病毒系非持續性的,蚜虫一次吸毒后,传病期不超过20分钟。两个以上的桃蚜传病率就可达100%。种子不传病。殘留在土壤內的新鮮病根,可以传病。蔊菜在自然情况下可以感染病害。病株上病毒可由蚜虫传至油菜而誘发典型的花叶病,且具有終年生长及終年发病的特性,可能成为初期发病的病毒来源。
译 名：
MOSAIC DISEASE OF CHINESE RAPE AND OTHER CRUCIFERS IN EASTERN CHINA
作 者：
SUMMARY WEI CHING TSAO (C. T. WEI). SHEN SHU-LIN (Nanking Agricultural Institute) WANG JUN-LIN (Chinese Academy of Agricultural Science) ZHANG CHENG-WAN (Sichuan Agricultural Experiment Station) AND ZHU YOU-GANG (Shenyang Agricultural Institute)
摘 要：
Chinese rape, varieties of Brassica campestris and B. chinensis and many cruciferous crops including radishes, but except varieties of B. oleracea, are generally affected by a mosaic disease, causing serious losses amounting occasionally to a death rate of over 90%, while an infection rate of over 30% is not uncommon. The symptoms involved were vein-clearing, yellow or green veinbanding, typical mosaic, rugosity of leaf lamina, dwarfing and rosetting. They may appear in different combinations. Flower stalks may not come out or are shortened, deformed and twisted. Flowers appeared pale yellow and become abortive, or forming only small and twisted seed pod, which are sometimes spotted with black necrosis, and bearing small and deformed seeds. When the winter temperature is low, diseased plants may succumb first, forming missing hills. Late infections may result only in vein-banding of the upper leaves and partial abortion of the seeds. On several varieties of radish, mostly of the green type, which apparently are more resistant, only fine mottling appears on the leaves while infected. On varieties of B. napella, another oil-bearing group, the symptoms are entirely different (plate 1, fig. 5), appearing as systemic bright yellow spots on the leaves. Necrotic flecking can eventually be found at the center of these spots. Necrotic streaks and spots develop on the flower stalks and seed pods. Dwarfing and distortion occur on leaves, stalks and pods, and death may even be resulted from severe infections. However, this species showed certain degree of resistance to the disease in the form of late infection and the lower incidence of the disease. The viruses from different host plants are cross-inoculable, although some strains do not infect B. napella. None of them can infect the cabbage group by sap inoculation. 3 viruses were identified: differentiated by their physical properties and the host reactions they induced (Tables 1 and 2 for the viruses 1 and 2): 1. Thermal inactivation below 70℃. 2. Producing necrotic local lesions only on N. tabacum var, "Nungling 400" …… virus 1 2. Producing necrotic local lesions and systemic mottling on the same host……virus 2 1. Thermal inactivation above 90℃., necrotic local lesions on N. glutinosa…… virus 3 The first two viruses can be subdivided into 2 strains each by their ability to infect B. napella. Virus 1 is considered to be a strain of Brassica virus 2 or the Turnip mosaic virus; from the type, it differs in not infecting the cabbage group. Virus 2 is identified as a strain of Cucumis virus 1 or the Cucumber mosaic; virus; from the type, it differs in having lower thermal inactivation point (55℃.), lower dilution end point (1: 1,000—3,000); and shorter longevity invitro (2 days), in producing local lesions on tobacco, and in that the typical strain of Cacumis virus 1 gives only a partial protection to this strain on tobacco. The 3rd virus was less studied. It shows affinity to Nicotiana virus 1 or the tobacco mosaic virus. A limited test showed that the first virus was the only virus found present in the field in 1957. An analysis of 17 isolates of virus from the Chinese rape, exhibiting various syndromes of symptoms in the field, gave an Unanimous result in host reactions, indicating that these isolates belong to a single virus. Virus 1 was found to be easily transmitted by sap, by aphids, including peach aphid (Myzus pcrsicae), false cabbage aphid (Rhopalosiphum pseudobrassicae), and cotton aphid (Aphis gossypii). In insect relationship, the virus belongs to the nonpersistent group, a single feeding will enable an active transmission of about 20 minutes. Peach aphid seems to be an effective vector that 2 or more viruliferous aphids per plant are capable of 100% transmission. The virus is not seed-transmitted. Fresh residue of diseased plant in the soil may cause occasional infection of the replanted plants. The virus can infect several cruciferous weeds, but, among them, only Rorippa montana (wall.) Small grows all the year round and possesses a perennial crown. It is also foundto be commonly infected in the nature. Rubbing with infected sap or using aphid as vector, the virus from this weed can easily be transmitted to the Chinese rape, producing the typical mosaic symptoms. This weed, therefore, seems to be capable of beoming a source of inoculum for the primary infection of the Chinese rape.
