scholarly journals Screening of Abelmoschus esculentus and Abelmoschus callei cultivars for resistance against okra leaf curl and okra mosaic viral diseases, under field conditions in South Eastern Nigeria

2014 ◽  
Vol 13 (48) ◽  
pp. 4419-4429 ◽  
Author(s):  
Obi Sergius Udengwu ◽  
Uju Esther Dibua
2018 ◽  
Vol 25 (5) ◽  
pp. 482-502 ◽  
Author(s):  
Yogendra Yadav ◽  
Praveen Kumar Maurya ◽  
Swadesh Banerjee ◽  
Tridip Bhattacharjee ◽  
Imtinungsang Jamir ◽  
...  

2005 ◽  
Vol 95 (5) ◽  
pp. 549-555 ◽  
Author(s):  
C. M. Fauquet ◽  
S. Sawyer ◽  
A. M. Idris ◽  
J. K. Brown

Numerous whitefly-transmitted viral diseases of tomato have emerged in countries around the Nile and Mediterranean Basins the last 20 years. These diseases are caused by monopartite geminiviruses (family Gemini viridae) belonging to the genus Begomovirus that probably resulted from numerous recombination events. The molecular biodiversity of these viruses was investigated to better appreciate the role and importance of recombination and to better clarify the phylogenetic relationships and classification of these viruses. The analysis partitioned the tomato-infecting begomoviruses from this region into two major clades, Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus. Phylogenetic and pairwise analyses together with an evaluation for gene conversion were performed from which taxonomic classification and virus biodiversity conclusions were drawn. Six recombination hotspots and three homogeneous zones within the genome were identified among the tomatoinfecting isolates and species examined here, suggesting that the recombination events identified were not random occurrences.


1977 ◽  
Vol 17 (89) ◽  
pp. 1032 ◽  
Author(s):  
AL Bishop ◽  
RE Day ◽  
PRB Blood ◽  
JP Evenson

Damage by the cotton tipworm, Crocidosema plebeiana Zeller, was simulated in field trials by the removal of terminal buds (tipping) at different phenological stages coinciding with tipworm presence on cotton grown in south-eastern Queensland. The effect of this damage was considered in relation to the induced changes in crop morphology, fruit production, yield and harvestability of cotton grown under field conditions. No significant differences in fruit formation and yield were established. There were significant delays in times to 50 per cent flowering and boll opening in plants tipped before squaring had commenced. Changes in the location of monopodial branches arising from the main stem were induced in plants tipped pre-squaring but this did not significantly affect the harvestability.


2019 ◽  
Vol 52 (9-10) ◽  
pp. 917-929
Author(s):  
Marzieh Shamshiri ◽  
Jahangir Heydarnejad ◽  
Mehdi Kamali ◽  
Najmeh Pouramini ◽  
Hossain Massumi

2018 ◽  
Vol 20 (5) ◽  
pp. 1-16
Author(s):  
Elvis Asare-Bediako ◽  
Faustina Agyarko ◽  
Kingsley Taah ◽  
Aaron Asare ◽  
Justice Sarfo ◽  
...  

2005 ◽  
Vol 53 (3) ◽  
pp. 225 ◽  
Author(s):  
Gabrielle Vivian-Smith ◽  
F. Dane Panetta

We investigated germination, seedling emergence and seed persistence of the invasive moth vine (Araujia sericifera Brot.) under controlled and field conditions in south-eastern Queensland. Fresh seed showed high viability (99.5%) and germinated readily, with 97.2% of all recorded germinations occurring within 14 days. Mean germination rates ranged from 74 to 100% across the range of temperature (10/20°C, 15/25°C and 20/30°C alternating 12-h thermoperiods) and light (0- and 12-h photoperiods) treatments. Germination was significantly reduced only under cool, dark conditions. In a 24-month field experiment, seedling emergence was greatest for seeds buried at 1 cm (mean = 96.3%), intermediate for seeds buried at 5 cm (mean = 62.7%) and least for surface-sown seeds (mean = 30.7%). Seed persistence under field conditions was low, declining rapidly to 3.9% at 6 months and to 0.67% at 24 months. Moth vine’s capacity to germinate readily and the rapid depletion of seeds under field conditions indicate that the species has a transient seed bank in south-eastern Queensland. In an additional experiment testing the capacity of seeds for secondary dispersal by water, the mean floating time of seeds was 15.4 days, suggesting that water could act as a secondary dispersal vector, contributing to long-distance dispersal. We recommend that surveillance methods for detecting moth-vine populations should consider both water-flow patterns and wind direction.


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