[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser ...[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.展开更多
Present work highlights, first time in Egypt, the impact of OYDV infection on crops production. Plants grown in the field were individually labelled as either apparently healthy or diseased and were marked for harvest...Present work highlights, first time in Egypt, the impact of OYDV infection on crops production. Plants grown in the field were individually labelled as either apparently healthy or diseased and were marked for harvesting. The percentage of yield loss due to viral infection was determined, on the basis of the average yield parameters of the healthy plant. The natural infection with OYDV in onion and garlic fields resulted in a substantial reduction in pseudo-stem length, number of leaves, plant weight and weight of bulb as well as number and weight of cloves. Results clearly indicate the impact of natural infection with OYDV on the crop yield of infected onion and garlic plants in comparison with the virus-free （uninfected） ones. The largest reduction in the yield of infected plants occurred in Chinese garlic （Seds40） followed by （Baladi） garlic and onion Giza 20. This information suggests that measures have to be taken to prevent natural infection with OYDV into and within onion and garlic fields in order to avoid yield loss.展开更多
Three pairs of primers were designed and synthesized from nucleotide sequences of garlic latent virus （GLV）, onion yellow dwarf virus （OYDV）, and leek yellow stripe virus （LYSV） by using PCR primer design softwa...Three pairs of primers were designed and synthesized from nucleotide sequences of garlic latent virus （GLV）, onion yellow dwarf virus （OYDV）, and leek yellow stripe virus （LYSV） by using PCR primer design software. The expected fragments about 170 bp, 287 bp, and 191 bp were amplified by RT-PCR for GLV, OYDV, and LYSV, respectively in disease-infected plants of potato onion （Allium cepa L., Aggregatum group）, but such fragments were not obtained from healthy-looking plants and virus-free seedlings of shoot-tips. The amplified products ofGLV, OYDV and LYSV were cloned into pGEM-T vectors, and transformed into Escherichia coli. JM109. The recombinant plasmids were obtained and sequenced. The nucleotide sequences were compared with corresponding viral nucleotide sequences reported in GenBank by performing a NCBI BLAST. The analysis showed that their homology attained 75% to 90%,89.5% to 96.1%,and 91.6% to 96.3% in GLV, OYDV, and LYSV, respectively. The total RNA of 6.34 ug·uL^-1 from infected plants was diluted to a series of 10^-1 to 10^5 and the detection sensitivity of RT-PCR was 10^4 （about 4 ng）. Thus, a method of identification and detection by RT-PCR of GLV, OYDV, and SLYV was established.展开更多
The nucleotide sequence of shallot yellow stripe virus from onion(SYSV-O)in Shaanxi Province of China was described.It was 10427 nucleotides(nt)in length excluding the poly(A)tail and was predicted to encode a polypro...The nucleotide sequence of shallot yellow stripe virus from onion(SYSV-O)in Shaanxi Province of China was described.It was 10427 nucleotides(nt)in length excluding the poly(A)tail and was predicted to encode a polyprotein of 3340 amino acids(aa)with a calculated molecular weight of 379.7kD.SYSV was most closely related to onion yellow dwarf virus(OYDV)and resembled it in having a much larger P3 protein than other species in the genus.SYSV-O shared 93.2% nt identity to the published sequence of a welsh onion isolate of SYSV(SYSV-ZQ2).The two isolates differed in NIb-CP cleavage site,that of SYSV-O was Q/V but Q/A in SYSV-ZQ2.Nucleotide identity of coat protein genes amongst all SYSV sequences ranged from 87.3%-84.1%.Phylogenetic tree analysis based on the 3’-terminal nucleotide sequences of SYSV isolates confirmed the existence of four distinct groups that were partially related to geographical origin and host plant species.展开更多
基金Supported by Natural Science Foundation of Sichuan Education Department(2008ZA033)
文摘[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.
文摘Present work highlights, first time in Egypt, the impact of OYDV infection on crops production. Plants grown in the field were individually labelled as either apparently healthy or diseased and were marked for harvesting. The percentage of yield loss due to viral infection was determined, on the basis of the average yield parameters of the healthy plant. The natural infection with OYDV in onion and garlic fields resulted in a substantial reduction in pseudo-stem length, number of leaves, plant weight and weight of bulb as well as number and weight of cloves. Results clearly indicate the impact of natural infection with OYDV on the crop yield of infected onion and garlic plants in comparison with the virus-free （uninfected） ones. The largest reduction in the yield of infected plants occurred in Chinese garlic （Seds40） followed by （Baladi） garlic and onion Giza 20. This information suggests that measures have to be taken to prevent natural infection with OYDV into and within onion and garlic fields in order to avoid yield loss.
基金Supported by Department Education of Heilongjiang Province of China (10531146)
文摘Three pairs of primers were designed and synthesized from nucleotide sequences of garlic latent virus （GLV）, onion yellow dwarf virus （OYDV）, and leek yellow stripe virus （LYSV） by using PCR primer design software. The expected fragments about 170 bp, 287 bp, and 191 bp were amplified by RT-PCR for GLV, OYDV, and LYSV, respectively in disease-infected plants of potato onion （Allium cepa L., Aggregatum group）, but such fragments were not obtained from healthy-looking plants and virus-free seedlings of shoot-tips. The amplified products ofGLV, OYDV and LYSV were cloned into pGEM-T vectors, and transformed into Escherichia coli. JM109. The recombinant plasmids were obtained and sequenced. The nucleotide sequences were compared with corresponding viral nucleotide sequences reported in GenBank by performing a NCBI BLAST. The analysis showed that their homology attained 75% to 90%,89.5% to 96.1%,and 91.6% to 96.3% in GLV, OYDV, and LYSV, respectively. The total RNA of 6.34 ug·uL^-1 from infected plants was diluted to a series of 10^-1 to 10^5 and the detection sensitivity of RT-PCR was 10^4 （about 4 ng）. Thus, a method of identification and detection by RT-PCR of GLV, OYDV, and SLYV was established.
文摘The nucleotide sequence of shallot yellow stripe virus from onion(SYSV-O)in Shaanxi Province of China was described.It was 10427 nucleotides(nt)in length excluding the poly(A)tail and was predicted to encode a polyprotein of 3340 amino acids(aa)with a calculated molecular weight of 379.7kD.SYSV was most closely related to onion yellow dwarf virus(OYDV)and resembled it in having a much larger P3 protein than other species in the genus.SYSV-O shared 93.2% nt identity to the published sequence of a welsh onion isolate of SYSV(SYSV-ZQ2).The two isolates differed in NIb-CP cleavage site,that of SYSV-O was Q/V but Q/A in SYSV-ZQ2.Nucleotide identity of coat protein genes amongst all SYSV sequences ranged from 87.3%-84.1%.Phylogenetic tree analysis based on the 3’-terminal nucleotide sequences of SYSV isolates confirmed the existence of four distinct groups that were partially related to geographical origin and host plant species.
