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Midatharahally Narasegowda Maruthi Henryk Czosnek Favi Vidavski Shlomo-Yedidia Tarba Judith Milo Shai Leviatov Hagalawadi Mallithimmaiah Venkatesh Attiganal Seetharam Padmaja Rudrappa Subbappa Kulkarni Venkataramappa Muniyappa 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):1-11
The objective of this study was to screen wild and domesticated tomatoes for resistance to Tomato yellow leaf curl virus, Israel (TYLCV-Is) and Tomato leaf curl virus from Bangalore isolate 4, India (ToLCV-[Ban4]) to find sources of resistance to both viruses. A total of 34 tomato genotypes resistant/tolerant to TYLCV-Is were screened for resistance to ToLCV-[Ban4] under glasshouse and field conditions at the University of Agricultural Sciences, Bangalore, India. Resistance was assessed by criteria like disease incidence, symptom severity and squash-blot hybridization. All the tomato genotypes inoculated with ToLCV-[Ban4] by the whitefly vector Bemisia tabaci (Gennadius) produced disease symptoms. In some plants of the lines 902 and 910, however, the virus was not detected by hybridization. The tomato genotypes susceptible to ToLCV-[Ban4] by whitefly-mediated inoculation were also found susceptible to the virus under field conditions. However, there were substantial differences between genotypes in disease incidence, spread, symptom severity and crop yield. Despite early disease incidence, many genotypes produced substantially higher yields than the local hybrid, Avinash-2. Sixteen tomato genotypes from India resistant/tolerant to ToLCV-[Ban4] were also tested for TYLCV-Is resistance at the Hebrew University of Jerusalem, Rehovot, Israel. Accessions of wild species, Lycopersicon hirsutum LA 1777 and PI 390659 were the best sources of resistance to both viruses. Lines 902 and 910, which were, resistant to TYLCV-Is were only tolerant to ToLCV-[Ban4] and accession Lycopersicon peruvianum CMV Sel. INRA, resistant to ToLCV-[Ban4], was only tolerant to TYLCV-Is. Implications of using the resistant lines in breeding programme is discussed. 相似文献
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Fengxiang X. Han W. Dean Patterson Yunju Xia B. B. Maruthi Sridhar Yi Su 《Water, air, and soil pollution》2006,170(1-4):161-171
The objectives of this study were to simplify sample preparation and validate mercury detection in soil and plant samples using inductively coupled plasma atomic emission spectroscopy (ICP-AES). A set of mercury contaminated and mercury free soil and plant samples were digested and analyzed by ICP-AES, inductively coupled plasma mass spectrometry (ICP-MS), and cold vapor atomic absorption spectroscopy (CVAAS). Results show that mercury measurements in soil and plant samples using ICP-AES were in agreement with those analyzed using ICP-MS and CVAAS. The concentrations of mercury in soils and plant tissues determined by ICP-AES were 92.2% and 90.5% of those determined by CVAAS and ICP-MS, respectively. Digestion of soil samples with 4 M HNO3 and direct measurement by ICP-AES without reduction of Hg2+ to Hg0 gave a reasonable and acceptable recovery (92%) for determining Hg in soils. We conclude that ICP-AES with optimized conditions (addition of gold chloride, extension of washing time, linear working range, and selection of wavelength – 194 nm) resulted in reliable detection of mercury in environmental samples. 相似文献
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M. S. Pallavi H. K. Ramappa K. S. Shankarappa K. T. Rangaswamy W. A. R. T. Wickramaarachchi M. N. Maruthi 《Phytoparasitica》2012,40(3):279-286
Chickpea (Cicer arietinum L.) plants showing typical symptoms of infection by a phytoplasma that causes phyllody disease have been commonly observed in recent years in parts of south India. The symptoms included pale green leaves, bushy appearance due to excessive stunting of shoots, reduced internodal length and excessive axillary proliferation. The causal agent of the phyllody disease was identified based on symptoms, amplification of 16S rDNA of the phytoplasma by polymerase chain reaction (PCR) from infected samples, as well as by sequencing and phylogenetic analysis. First round PCR and nested-PCR protocols were standardized for improved efficiency and reliability of the diagnostic protocols. Using the primers P1/P7 and R16F2n/R16R2, 1,800?bp and 1,200?bp size products were amplified in first round PCR and nested-PCR protocols, respectively. The PCR product was cloned and sequenced and compared with the reference phytoplasma sequences from the database (NCBI). The Indian chickpea phyllody phytoplasma 16S rDNA sequences shared the highest nucleotide identity (>98%) with the 16S rII group phytoplasma candidates, also infecting chickpea from Australia and Pakistan. This is the first report of a phytoplasma of the 16SrII-group infecting chickpea from India. The genetic similarities and the potential threat of this new disease to chickpea cultivation in India are discussed. 相似文献
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K. L. Sharma D. Suma Chandrika J. Kusuma Grace G.R. Maruthi Shankar S. K. Sharma H. S. Thakur 《Communications in Soil Science and Plant Analysis》2016,47(12):1465-1475
Vertisol soils of central India are heavy in texture, with high clay content and low organic matter. These soils are prone to degradation and the soil loss is due to poor management practices including excessive tillage. Based on a long-term study conducted for improving the quality of these soils, it was found that management practice such as low tillage (LT) + 4 t ha?1 compost + herbicide (Hb) recorded significantly higher organic carbon (OC) (6.22 g kg?1) and available N (188.5 kg ha?1) compared to conventional tillage (CT) + recommended fertilizer (RF) + off-season tillage (OT) + hand weeding (HW) (OC: 4.71 g kg?1, available nitrogen (N) (159.3 kg ha?1). Among the physical soil quality parameters, mean weight diameter (MWD) was significantly higher under LT + 4 t ha?1 straw + Hb (0.59 mm). The practice of LT + 4 t ha?1 straw + HW recorded significantly higher microbial biomass carbon (MBC) (388.8 μg g?1). The order of key indicators and their contribution towards soil quality was as follows: OC (29%) >, MBC (27%) > available zinc (Zn) (22%) > MWD (9%) > available boron (B) (8%), > dehydrogenase activity (DHA) (5%). The order of the best treatment which maintained soil quality index (SQI) values reasonably good (>1.5) was as follows: LT + 4t ha?1 compost + HW (1.65) > LT + 4 t ha?1 compost +Hb (1.60) > LT + 4t ha?1 straw + HW (1.50). Hence, these treatments could be recommended to the farmers for maintaining higher soil quality in Vertisols under soybean system. Correlation studies revealed stronger relationship between key indicators like OC (R2 = 0.627), MBC (R2 = 0.884), available Zn (R2 = 0.739) and DHA (R2 = 0.604) with Relative Soil Quality Index (RSQI). The results of the present study would be highly useful to the researchers, farmers and land managers. 相似文献
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Saptarshi Ghosh Sophie Bouvaine Simon C. W. Richardson Murad Ghanim M. N. Maruthi 《Journal of pest science》2018,91(1):17-28
We investigated the dual effects of bacterial infections and diseased cassava plants on the fitness and biology of the Bemisia tabaci infesting cassava in Africa. Isofemale B. tabaci colonies of sub-Saharan Africa 1-subgroup 3 (SSA1-SG3), infected with two secondary endosymbiotic bacteria Arsenophonus and Rickettsia (AR+) and those free of AR infections (AR?), were compared for fitness parameters on healthy and East African cassava mosaic virus-Uganda variant (EACMV-UG)-infected cassava plants. The whitefly fecundity and nymph development was not affected by bacterial infections or the infection of cassava by the virus. However, emergence of adults from nymphs was 50 and 17% higher by AR? on healthy and virus-infected plants, respectively, than AR+ flies. Development time of adults also was 10 days longer in AR+ than AR?. The whiteflies were further compared for acquisition and retention of EACMV-UG. Higher proportion of AR? acquired (91.8%) and retained (87.6%) the virus than AR+ (71.8, 61.2%, respectively). Similarly, the AR? flies retained higher quantities of virus (~ninefold more) than AR+. These results indicated that bacteria-free whiteflies were superior and better transmitters of EACMV-UG, as they had higher adult emergence, quicker life cycle and better virus retention abilities than those infected with bacteria. 相似文献
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ABSTRACT The molecular diversity of Tomato leaf curl viruses (ToLCVs), from the two main tomato growing areas of Jessore and Joydebpur, Bangladesh, was investigated. The viral DNA was amplified from tomato plants exhibiting mild and severe symptoms by polymerase chain reaction, and the complete genomes of the ToLCVs were sequenced. An isolate of the bipartite Tomato leaf curl New Delhi virus-Severe (ToLCNDV-Svr) was associated with the severe symptom phenotype from Jessore (ToLCNDV-Svr[Jes]). A previously undescribed monopartite virus, designated Tomato leaf curl Joydebpur virus-Mild (ToLCJV-Mld), was sequenced from plants showing mild symptoms. ToLCNDV-Svr[Jes] was most closely related to ToLCNDV-[Lucknow] at 95.7% nucleotide (nt) identity and Tomato leaf curl Gujarat virus-[Varanasi] at 90.6% nt identity, based on DNA-A and -B component sequences. ToLCJV-Mld was similar to Pepper leaf curl Bangladesh virus at 87.1% DNA-A nt identity. Identification of ToLCNDV-Svr[Jes] and ToLCJV-Mld was in addition to the previously described Tomato leaf curl Bangladesh virus, with which they shared 73.2 and 86.0% DNA-A nt identities, thus demonstrating the existence of at least three distinct viruses infecting tomato in Bangladesh. Nucleotide identities and placement in phylogenetic trees suggested that the three ToLCVs may have had different evolutionary pathways. The whitefly, Bemisia tabaci, transmitted the viruses of this study equally efficiently. Four tomato cultivars (TLB111, TLB130, TLB133, and TLB182) resistant/ tolerant to South Indian ToLCV were screened against the Bangladesh ToLCVs in 2003-04. Although challenged by diverse viruses and potentially mixed infections, disease incidence remained low (6 to 45%) in the resistant cultivars compared with local cultivars (68 to 100%). 相似文献
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Phytoparasitica - Interactions among the four biotic agents - the host plants, a virus, insect vector whiteflies and their bacterial endosymbionts was investigated in this study. The whitefly... 相似文献
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The phenomenon of virus‐infected plants naturally recovering health is known as ‘reversion’, and is a type of resistance mechanism exploited in some crop plants for disease control. Various parameters were investigated that affect reversion from cassava brown streak disease (CBSD) in three cassava varieties (Albert, Kaleso and Kiroba) that differ in levels of resistance to the disease. Cassava plants were inoculated by grafting with two virus species (Ugandan cassava brown streak virus, UCBSV and Cassava brown streak virus, CBSV) that cause CBSD, and the plants grown from them were subsequently assessed for reversion. The rate of reversion depended on the cassava variety, virus species, and the length and position of the stem cuttings used. A significantly high proportion of progenies were virus‐free (reverted) for the resistant variety Kaleso (64·1% for UCBSV and 54·9% of CBSV), compared to the tolerant variety Kiroba (56·7 and 45·5%) and the susceptible control Albert (38·9 and 35·1%). The highest number of virus‐free plants was generated from short 10 cm long cuttings (e.g. 60·1% for Kaleso for CBSV) compared to 20 cm long stem cuttings (e.g. 21·4% for Albert). Cuttings taken from upper stems of diseased plants produced most virus‐free progenies compared to middle and lower parts. More than 50% virus‐free plants were obtained in the resistant and tolerant varieties. This is a highly valuable finding and could be exploited for developing strategies to control the current CBSD epidemic in eastern and central Africa. 相似文献