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Clubroot disease caused by Plasmodiophora brassicae is becoming a serious threat to rapeseed (Brassica napus) production worldwide. Breeding resistant varieties using CR (clubroot resistance) loci is the most promising solution. Using marker‐assisted selection and speed‐breeding technologies, we generated Brassica napus materials in homozygous or heterozygous states using CRA3.7, CRA08.1, and CRA3.2 loci in the elite parental line of the Zhongshuang11 background. We developed three elite lines with two CR loci in different combinations and one line with three CR loci at the homozygous state. In our study, we used six different clubroot strains (Xinmin, Lincang, Yuxi, Chengdu, Chongqing, and Jixi) which are categorized into three groups based on our screening results. The newly pyramided lines with two or more CR loci displayed better disease resistance than the parental lines carrying single CR loci. There is an obvious gene dosage effect between CR loci and disease resistance levels. For example, pyramided lines with triple CR loci in the homozygous state showed superior resistance for all pathogens tested. Moreover, CR loci in the homozygous state are better on disease resistance than the heterozygous state. More importantly, no negative effect was observed on agronomic traits for the presence of multiple CR loci in the same background. Overall, these data suggest that the pyramiding of triple clubroot resistance loci conferred superior resistance with no negative effects on agronomic traits in Brassica napus. [ABSTRACT FROM AUTHOR]

Clubroot, caused by Plasmodiophora brassicae is one of the most severe threats to brassica species in China and worldwide. Breeding for clubroot resistant varieties is one of the best ways to overcome this disease. In this study, we introduced clubroot resistance (CR) gene CRd from Chinese cabbage (85-74) into elite Brassica napus inbred line Zhongshuang 11 through interspecific hybridization and subsequent backcrossing with whole-genome molecular marker-assisted selection (MAS). The resistant test of CRd to P. brassicae isolates was evaluated in the greenhouse as well as in field conditions. Close linkage markers and the wholechromosome background marker selection approach improved the recovery rate from 78.3% in BC1 to 100% in BC3F1. The improved clubroot-resistant variety, Zhongshuang11R, was successfully selected in the BC3F2 generation. The greenhouse and field resistant tests revealed that Zhongshuang11R was resistant to P. brassicae pathotypes. The agronomic characteristics of Zhongshuang11R were similar to those of its recurrent parental line, including oil content, composition of fatty acid, plant height, primary effective branches, grain yield per plant and thousand-seed weight. In addition, the oil quality could satisfy the quality requirements for commercial rapeseed oil. Our results will enrich the resistant resources of canola and will certainly accelerate clubroot resistance breeding programs in B. napus. [ABSTRACT FROM AUTHOR]

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The experiment was planned to study the pathogenicity test and inoculum levels of most predominant fungus Fusarium oxysporum on bottle gourd. The pathogenicity test of F. oxysporum showed that the minimum number of germinated seeds were recorded from inoculated seeds, while, the maximum number of germinated seeds were recorded from uninoculated seeds. The effectiveness of different inoculum levels showed uninoculated untreated found to be the best for germination of bottle gourd seeds, plant growth (root, shoot and total plant length and weight) and leave infection percentage followed by 5% inoculum, 10% inoculum and 15% inoculum. The maximum mortality of plant was recorded at maximum inoculum level (30%) followed by 25, 20, 15, 10 and 5%. [ABSTRACT FROM AUTHOR]

A field trial was conducted to examine the effect of integrated application of urea and FYM on the fodder yield of maize. N in the form of urea at the rates of 0, 60, 90, 120 and 150 kg ha-1 and FYM at the rates of 1500, 3000 and 4500 kg ha-1 were applied separately and in all possible combinations. The experiment was conducted in a three replicated Randomized Complete Block Design. The results revealed significant (P<0.05) influence of different N and FYM levels on all the parameters studied. The maize grown under T20 (N 150 kg ha-1 + FYM 4500 kg ha-1) performed maximally with 90.48% germination, 200 cm plant height, 9.20 nodes plant-1, 8.28 internodes plant-1, 15.73 green leaves plant-1, 48.77 cm leaf length, 5.85 cm leaf width, 2.36 dry leaves plant-1, 4.88 cm stem girth and 42200 kg green fodder yield ha-1. Reducing FYM (T19=N 150 kg + FYM 3000 kg ha-1) resulted a reduced fodder yield with 87.52% germination, 190.33 cm plant height, 8.76 nodes plant-1, 7.88 internodes plant-1, 14.97 green leaves plant-1, 46.41 cm leaf length, 5.57 cm leaf width, 2.24 dry leaves plant-1, 4.64 cm stem girth and 38257 kg green fodder yield ha-1. Effect of separate FYM indicates that crop performance was relatively higher under 4500 kg ha-1 FYM than lower FYM levels. In separate N treatment, the maize performance was higher under 150 kg ha-1 N as compared to lower N levels. There was remarkable effect of combining N and FYM on fodder yield and its components, and N alone or FYM alone could not produce such level of fodder yields. Nevertheless, higher fodder yields in maize could be achieved by fertilizing only with inorganic nitrogen at higher levels (without FYM), but the desired yields cannot be achieved with FYM as sole nutrient application (without inorganic N). However, FYM was mainly effective to improve germination, because it is applied before sowing, and it activates the soil microorganisms that results in improved germination. It was concluded that for achieving high green fodder yields in maize, the crop may be fertilized with 150 kg ha-1 N in addition to 4500 kg ha-1 well rotten farm yard manure. [ABSTRACT FROM AUTHOR]

Macrophomina phaseolina was isolated as root infecting fungi from okra plants showing stunted growth, necrosis and severe plant mortality. The pathogenecity test, has confirmed that M. phaseolina is an aggressive pathogen of okra plant. Bio-control agents including Trichoderma spp., Paecilomyces spp. and Gliocladium virens successfully checked the mycelial growth of the M. phaseolina in dual assay test; however P. variotii followed by T. harzianum, T. pseudokoningii and T. polysporum were the most effective bio-control agents in inhibiting the colony growth of test pathogen. In pot experiment, application of bio-control agents greatly reduced the root infection in plants grown in soil, artificially infested with M. phaseolina. Among six bio-control agents, T. harzianum and P. variotii appeared as highly effective in reducing the root infection by test pathogen. The highest root infection was found in plants treated with T. pseudokoningii followed by P. lilacinus. The application of these bio-control agents also caused positive impact on plant growth. Moreover, these bio-control agents also checked the pathogen infection and thus increased seed germination and decreased plant mortality. [ABSTRACT FROM AUTHOR]