scholarly journals Development of Bacterial Spot on Near-Isogenic Lines of Bell Pepper Carrying Gene Pyramids Composed of Defeated Major Resistance Genes

1999 ◽  
Vol 89 (11) ◽  
pp. 1066-1072 ◽  
Author(s):  
C. S. Kousik ◽  
D. F. Ritchie
Keyword(s):  
Disease Severity ◽  
Resistance Genes ◽  
Field Studies ◽  
Residual Effects ◽  
Specific Gene ◽  
Near Isogenic Lines ◽  
Bacterial Spot ◽  
Isogenic Lines ◽  
Major Resistance Genes ◽  
Race 4

Disease severity caused by races 1 through 6 of Xanthomonas campestris pv. vesicatoria on eight near-isogenic lines (isolines) of Early Calwonder (ECW) with three major resistance genes (Bs1, Bs2, and Bs3) in different combinations was evaluated in the greenhouse and field. Strains representing races 1, 3, 4, and 6 caused similar high levels of disease severity, followed by races 2 and 5 on susceptible ECW. Race 3 caused severe disease on all isolines lacking resistance gene Bs2. Race 4, which defeats Bs1 and Bs2, caused less disease on isoline ECW-12R (carries Bs1 + Bs2), than on isolines ECW, ECW-10R (carries Bs1), and ECW-20R (carries Bs2). Similar results were obtained with race 4 strains in field studies conducted during 1997 and 1998. In greenhouse studies, race 6, which defeats all three major genes, caused less disease on isoline ECW-13R (carries Bs1 + Bs3) and ECW-123R (carries Bs1 + Bs2 + Bs3) than on isolines ECW, ECW-10R, ECW-20R, and ECW-30R (carries Bs3), but not on ECW-23R (carries Bs2 + Bs3). In greenhouse studies with commercial hybrids, strains of races 4 and 6 caused less disease on Boynton Bell (carries Bs1 + Bs2) than on Camelot (carries no known resistance genes), King Arthur (carries Bs1), and X3R Camelot (carries Bs2). Race 6 caused less disease on hybrid R6015 (carries Bs1 + Bs2 + Bs3) and Sentinel (carries Bs1 + Bs3) than on Camelot. Residual effects were not as evident in field studies with race 6 strains. Defeated major resistance genes deployed in specific gene combinations (i.e., gene pyramids) were associated with less area under the disease progress curve than when genes were deployed individually in isolines of ECW or commercial hybrids. Successful management of bacterial spot of pepper is achieved incrementally by integrating multiple tactics. Although there is evidence of residual effects from defeated genes, these effects alone likely will not provide acceptable bacterial spot control in commercial production fields. However, when combined with sanitation practices and a judicious spray program, pyramids of defeated resistance genes may aid in reducing the risk of major losses due to bacterial spot.

scholarly journals The Impact of Climate Change on the Resistance of Rice Near-Isogenic Lines with Resistance Genes Against Brown Planthopper

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yun-Hung Kuang ◽  
Yu-Fu Fang ◽  
Shau-Ching Lin ◽  
Shin-Fu Tsai ◽  
Zhi-Wei Yang ◽  
...  
Keyword(s):  
Climate Change ◽  
Resistance Genes ◽  
Environmental Changes ◽  
Gene Pyramiding ◽  
Brown Planthopper ◽  
Inhibitory Effect ◽  
Near Isogenic Lines ◽  
Impact Of Climate Change ◽  
Isogenic Lines ◽  
The Impact

Abstract Background The impact of climate change on insect resistance genes is elusive. Hence, we investigated the responses of rice near-isogenic lines (NILs) that carry resistance genes against brown planthopper (BPH) under different environmental conditions. Results We tested these NILs under three environmental settings (the atmospheric temperature with corresponding carbon dioxide at the ambient, year 2050 and year 2100) based on the Intergovernmental Panel on Climate Change prediction. Comparing between different environments, two of nine NILs that carried a single BPH-resistant gene maintained their resistance under the environmental changes, whereas two of three NILs showed gene pyramiding with two maintained BPH resistance genes despite the environmental changes. In addition, two NILs (NIL-BPH17 and NIL-BPH20) were examined in their antibiosis and antixenosis effects under these environmental changes. BPH showed different responses to these two NILs, where the inhibitory effect of NIL-BPH17 on the BPH growth and development was unaffected, while NIL-BPH20 may have lost its resistance during the environmental changes. Conclusion Our results indicate that BPH resistance genes could be affected by climate change. NIL-BPH17 has a strong inhibitory effect on BPH feeding on phloem and would be unaffected by environmental changes, while NIL-BPH20 would lose its ability during the environmental changes.

A set of near-isogenic lines for blast resistance genes with an Indica-type rainfed lowland elite rice (Oryza sativa L.) genetic background

2011 ◽  
Vol 123 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Yohei Koide ◽  
Leodegario A. Ebron ◽  
Hiroshi Kato ◽  
Hiroshi Tsunematsu ◽  
Mary Jeanie Telebanco-Yanoria ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Resistance Genes ◽  
Genetic Background ◽  
Oryza Sativa L ◽  
Blast Resistance ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
Rainfed Lowland ◽  
Blast Resistance Genes

scholarly journals Response of Bell Pepper Cultivars to Bacterial Spot Pathogen Races that Individually Overcome Major Resistance Genes

Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 181-186 ◽  
Author(s):  
C. S. Kousik ◽  
D. F. Ritchie
Keyword(s):  
Resistance Genes ◽  
Xanthomonas Campestris ◽  
Field Experiments ◽  
King Arthur ◽  
Bacterial Spot ◽  
Initial Inoculum ◽  
Bell Peppers ◽  
Or Gene ◽  
Major Resistance Genes ◽  
Significant Disease

The effect of major resistance genes (Bs1, Bs2, and Bs3) or gene combinations for resistance to bacterial spot of bell peppers (Xanthomonas campestris pv. vesicatoria) in 15 commercial cultivars on disease reduction and yield were studied during 1995 and 1996. Reaction of cultivars to specific races (races 1, 2, or 3) of the pathogen corresponded with seed company claims for resistance against these races. Races 1 to 4 were used as initial inoculum in 1995, and races 1 to 6 in 1996 field experiments. Cultivars with no known resistance genes to bacterial spot (e.g., Camelot, Jupiter, and Valiant), a single resistance gene (X3R Camelot, King Arthur), or a combination of Bs1 and Bs3 genes (Guardian, Sentinel, and Admiral) were severely diseased. Yields were reduced in all inoculated cultivars compared to non-inoculated cultivars used as controls. Although races 4 and 6 caused significant disease in cultivars with only Bs1 (King Arthur) or Bs2 (X3R Camelot) genes, cultivars with a combination of Bs1 and Bs2 (Boynton Bell, PR9300-8) had much lower levels of bacterial spot. Roger 4178, a hybrid with a combination of Bs1, Bs2, and Bs3 genes, had the lowest disease ratings. Overall, race 3 was predominant during 1995, while races 3 and 6 were recovered most frequently in 1996.

scholarly journals Development of a PCR-based Marker Set for Identifying Koshihikari Niigata BLs, Near-isogenic Lines Harboring Rice Blast Resistance Genes

2006 ◽  
Vol 8 (3) ◽  
pp. 79-87 ◽  
Author(s):  
Sumiko Nakamura ◽  
Keitaro Suzuki ◽  
Yoshiyuki Ban ◽  
Tsuneo Nishikawa ◽  
Kunio Tokunaga ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Blast Resistance ◽  
Near Isogenic Lines ◽  
Rice Blast Resistance ◽  
Isogenic Lines ◽  
Blast Resistance Genes

scholarly journals Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot

2018 ◽  
Vol 108 (2) ◽  
pp. 196-205 ◽  
Author(s):  
A. Strayer-Scherer ◽  
Y. Y. Liao ◽  
M. Young ◽  
L. Ritchie ◽  
G. E. Vallad ◽  
...  
Keyword(s):  
Disease Severity ◽  
Metallic Copper ◽  
Field Studies ◽  
Bacterial Disease ◽  
Bacterial Spot ◽  
Water Control ◽  
Xanthomonas Perforans ◽  
Bacterial Spot Disease ◽  
Copper Tolerant

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P < 0.05). All copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P < 0.05). Although there was no significant impact on yield, copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P < 0.05). This study highlights the discovery that copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

scholarly journals Virulence of Xanthomonas oryzae pv. oryzae on Rice Lines Containing Single Resistance Genes and Gene Combinations

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Tika B. Adhikari ◽  
Ram Chandra Basnyat ◽  
T. W. Mew
Keyword(s):  
Resistance Genes ◽  
Effective Resistance ◽  
Xanthomonas Oryzae ◽  
The Other ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
Gene Combination ◽  
Group I ◽  
Virulence Group

Fifty isolates of Xanthomonas oryzae pv. oryzae were collected from different rice-producing districts of Nepal and evaluated for their virulence on these 11 rice lines having from one to four resistance genes: IRBB4 (Xa4), IRBB5 (xa5), IRBB7 (Xa7), IRBB8 (xa8), IRBB10 (Xa10), IRBB14 (Xa14), and IRBB21 (Xa21), two-gene combination AY4+5 (Xa4 and xa5), three-gene combinations NH21-37-1-1 (Xa4, xa5, and xa13) and NH24-10-1-3 (Xa4, xa5, and Xa21), and four-gene combination NH56-1-44-4 (Xa4, xa5, xa13, and Xa21). The ability of an isolate to cause lesions with different lengths across the lines was interpreted as virulence. Isolates that were consistently associated with high or low virulence were statistically differentiated. Most isolates produced large lesions on near-isogenic lines with single genes and small lesions on lines with different gene combinations. Based on infection responses on the two-, three-, and four-gene combinations, five virulence groups were identified. Isolates in virulence group I were widely distributed. The line × isolate interactions were generally not significant with gene combinations, indicating a low possibility of specificity. A line with a four-gene combination, NH56, showed wider spectrum and higher level of resistance to X. oryzae pv. oryzae than the other lines. The results of this study will facilitate the deployment of effective resistance to X. oryzae pv. oryzae in Nepal.

Occurrence of wheat leaf rust (Puccinia triticina) races and virulence changes in Slovakia in 1994–2004

Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Alena Hanzalová ◽  
Jozef Huszár ◽  
Pavel Bartoš ◽  
Eva Herzová
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Field Tests ◽  
Puccinia Triticina ◽  
Near Isogenic Lines ◽  
Wheat Leaf Rust ◽  
Good Resistance ◽  
Isogenic Lines ◽  
Wheat Leaf

AbstractIn 1995–2004 we investigated leaf rust virulence in Slovakia on Thatcher near isogenic lines (NILs) with genes Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr10, Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. According to reaction of leaf rust isolates resistance genes Lr9 and Lr19 were completely effective to all examined pathotypes in all years. The resistance genes Lr24 and Lr28 were also completely effective to all examined pathotypes till the year 2001. In the year 2001 we detected 20% and 10% virulent isolates on NILs Lr24 and Lr28, respectively. According to the reaction of investigated isolates from the territory of Slovakia on NILs, resistance genes Lr2c, Lr3a, Lr11, Lr17, Lr21, Lr23 and Lr26 were mostly ineffective.During the 1994–2004 period we detected 16 races of leaf rust (races 2, 2SaBa, 6, 6SaBa, 12, 12SaBa, 14, 14SaBa, 57, 57SaBa, 61, 61SaBa, 62SaBa, 77, 77SaBa, 77/57SaBa). The most frequently determined races were 61SaBa and 77SaBa, which occurred in all years. Among frequently determined races we can assign race 12SaBa as well.According to the field tests in 2001–2004 good resistance to leaf rust was displayed by the cvs Arida (Lr13, Lru), Eva (Lr3, Lru) and Solara (Lru).

Sign in / Sign up

Export Citation Format

Share Document