Incubation Period In Plants Research Articles

Effect Local Microorganisms Coconut Pulp in Increasing The Resistance of Red Chilli Plants To Fungus Colletotrichum acutatum J.H. Simmonds

The fungus Colletotrichum acutatum which often attacks chili plants causes anthracnose disease. Farmers generally use fungicides to control this disease. Continuous use of synthetic fungicides will have negative impacts. Plant extracts as an alternative to natural fungicides can be an appropriate and environmentally friendly choice. One of them is the use of Local Microorganisms (MOL). This research aims to determine the optimal concentration of coconut pulp MOL in increasing the resistance of red chilli plants to the fungus Colletotrichum acutatum that causes anthracnose disease. The study used a Totally Randomized Design (CRD) with 6 drugs, namely A (0 ml/water), B (5 ml/water), C (10 ml/water), D (15 ml/water), E (20 ml/water). ml/water), F (25 ml/water). There are four treatments each time. Information was broken down using ANOVA and continued with the Fair Genuine Contrast (BNJ) test at the 5% level (α = 5%). with a level of 5% (α = 5%). The results showed a significant effect on fungal colony diameter, germination period, plant height, plant incubation period, and disease severity. The best concentration of local coconut pulp microorganisms in inhibiting anthracnose disease was 25 ml/l water.

Reaction of some commercial citrus species and Iranian lime biotypes to witches' broom disease of lime

Witches' broom disease of lime (WBDL), associated with Candidatus Phytoplasma aurantifolia, has devastated the majority of Mexican lime orchards in southern Iran. Recognition of resistant cultivars and rootstocks can play a major role in WBDL management. In this study, graft-inoculation was used to address the reaction of 12 citrus commercial species and 39 collected lime biotypes from five main lime production areas of Hormozgan province, Iran, against WBDL phytoplasma. The experimental plants were allowed to grow from seed, then five seedlings of each species and biotypes were grafted with Ca. Phytoplasma aurantifolia infected shoots. Inoculated plants were inspected for symptom expression for two years. Direct and nested-PCR using P1/P7 and R16F2n/R16R2 primer pairs, respectively, were used for confirmation of phytoplasmal infection in the suspected plants. All commercial citrus species and 39 of the lime biotypes showed the symptoms of little leaf, internode shortening and witches' broom after two to twenty months from graft-inoculation. Incubation period in plants varied from two months in Astaraei lemon and R11 biotype of Rudan region to twenty months in S4 and S6 biotypes of Senderk region. With these results, we can say all commercial citrus species were sensitive to WBDL. Among the commercial citrus species, Lisbon lemon, grapefruit and Cleopatra mandarin cultivars showed symptoms of WBDL after 460, 425 and 375 days, respectively. Disease symptoms developed rapidly on Astaraei lemon and Bakraei within 85–105 days, respectively. Among the collected biotypes, one, five and one biotypes from Minab, Rudan and Hashtbandi, respectively, were resistant to WBDL phytoplasma. These biotypes were symptomless; however, the PCR assay for detection of the phytoplasma was positive in all of them. These results are promising regarding the potential of using the suitable biotypes to reduce the development of WBDL.

Factors Affecting the Infection of Plants with Clover Phyllody Agent Transmitted by Macrosteles fascifrons1

Transmission of the clover phyllody agent (CPA) by female aster leafhoppers, Macrosteles fascifrons(Stål), was increased from 11 to 89% by increasing the inoculation access periods on aster seedlings from one hour to 7 days. No transmission was obtained with 0.5 hour feeds. When inoculative leafhoppers were given one-day inoculation access feeds on several species of plants, percentage transmission ranged from 10% for Potentilla intermedia L. to 100% for Thlaspi arvense L. The percentage of plants that developed symptoms varied with site of inoculation. New leaves were the most efficient site (49%), followed by the upper surface of the middle leaf (34%), lower surface of middle leaf (26%), old leaf (23%), and basal portion of main stem (9%). Two-week-old asters were more susceptible (87%) than were 4- (46%), 7- (72%), or 9- (65%) week-old plants. Female leafhoppers were considerably more efficient transmitters than were males when compared at inoculation access times ranging from one to 48 hours. The average incubation period in plants inoculated by females (23.1 clays) was shorter than in plants inoculated by males (27.6 days). Movement of CPA from its inoculation site in a leaf to the main stem of the plant occurred in periods ranging from less than 8 hours to more than 48 hours. All attempts to transmit CPA through eggs laid by inoculative M. fascifrons failed.

Possible multiplication in the aphid vector of sowthistle yellow vein virus, a virus with an extremely long insect latent period

Abstract Sowthistle yellow vein virus (SYVV) causes striking veinclearing and veinbanding in sowthistle (Sonchus oleraceus L.) and has transmission characteristics many of which are very similar or identical to those first described for plant-insect viruses transmitted by leafhoppers. An increase in aphid numbers increased transmission percentages and decreased the apparent latent period range, the average minimum latent period within the insects, and the average incubation period in all plants infected in series. The sowthistle aphid, Amphorophora lactucae (L.), may become viruliferous in a 2-hour acquisition feeding. Transmission, except for the percentage of insects that become viruliferous, was independent of the length of the acquisition feeding period. Efficiency of transmission following the latent period in the vector is higher than with any other vector known to the author. If one considers the latent period as starting with the beginning of the acquisition period then the minimum latent period in the aphid vector, as well as the time of retention of the virus by the aphid, were independent of the length of the acquisition feeding. Insects reared on diseased plants indicated that the entire latent period could be spent on diseased plants; such insects transmitted immediately after removal. The latent period of sowthistle yellow vein virus in its vector at various temperatures seemed to be negatively correlated with the activity of the insects as measured by longevity and nymph production. The shortest insect latent period recorded was 8 days at 25°C. The longest latent period was 46 days at 5°C. The first two or three infections induced by an aphid resulted in long incubation periods in infected plants. Later infections induced by the same aphid resulted in shorter incubation perods, but as an insect continued to transmit, the incubation periods again increased. The shortest plant incubation period observed was 7 days and the longest 55. The influence of various temperatures on incubation period in the plant was similar to the effects of temperature on the latent period of the virus in aphids. Nonviruliferous aphids acquired virus from inoculated plants as early as 5 days before symptom expression but never earlier than 6 days after inoculation. Individual insects transmitted SYVV 52 days after leaving diseased plants and probably retained the virus for the remainder of their life. Multiplication of SYVV in its aphid vector seems the most likely explanation for the observed relationships of the virus to the vector.

INCUBATION PERIOD OF ASTER‐YELLOWS VIRUS

American Journal of BotanyVolume 40, Issue 10 p. 797-809 Article INCUBATION PERIOD OF ASTER-YELLOWS VIRUS Karl Maramorosch, Karl Maramorosch The Laboratories of the Rockefeller Institute for Medical Research, New York, New YorkSearch for more papers by this author Karl Maramorosch, Karl Maramorosch The Laboratories of the Rockefeller Institute for Medical Research, New York, New YorkSearch for more papers by this author First published: 01 December 1953 https://doi.org/10.1002/j.1537-2197.1953.tb06557.xCitations: 14AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume40, Issue10December 1953Pages 797-809 RelatedInformation