Resistance Evaluation on Populations of Crosses Between Transgenic Potato Katahdin Rb and Non-transgenic Atlantic and Granola to Late Blight (Phytophthora Infestans) in Confined Field Trial

Late blight resistance gene (RB gene) isolated from Solanum bulbocastanum, is a broad resistance gene against all races of Phytophthora infestans. The gene was transformed into Katah-din event SP904 and SP951 using Agrobacterium tumefaciens and these transgenic plants have been crossed with susceptible potato cultivars Atlantic and Granola. Populations of the crosses have been molecularly characterized for the integration of the RB transgene. The study aimed to evaluate the resistance of the populations of crosses between transgenic Katahdin RB and susceptible non-transgenic parents (Atlantic and Granola) to late blight in a confined field trial at Pasir Sarongge, Cianjur, West Java. A total of 84 clones originated from four popula-tions were evaluated for resistance to late blight. These included 22 clones of Atlantic x transgenic Katahdin SP904, 16 clones of Atlantic x transgenic Katahdin SP951, 19 clones of Granola x transgenic Katahdin SP904, and 27 clones of Granola x transgenic Katahdin SP951. Observations of the late blight infection were conducted when late blight symptoms were detected, i.e. at 56, 60, 63, 70, and 77 days after planting (DAP). The result showed there were high variations in the resistance level of all the 84 clones tested. Clones of crosses between susceptible parents (Atlantic or Granola) and resistant parents (transgenic Katahdin SP904 or Katahdin SP951) showed a similar pattern based on the area under disease progress curve (AUDPC) value, i.e. 377.2 greater than the AUDPC of the resistant parents (180.1), but smaller than that of the susceptible parents (670.7). Observation at 77 DAP resulted four resistant potato clones having resistance score of 7.0-7.6, higher than the transgenic parents Katahdin SP904 (4.6) and Katahdin SP951 (6.8), i.e. clone B8 (Atlantic x transgenic Katahdin SP951) with resistance score of 7.6 and clones B26 (Atlantic x transgenic Katahdin SP951), C183 (Granola x transgenic Katahdin SP904), and D89 (Granola x transgenic Katahdin SP951) with resistance score of 7. These four transgenic potato resistant clones need to be further developed as promising potato clones to late blight

Evaluation for stable resistance to Stenocarpella maydis in tropical maize (Zea mays L.)

Maize ear rots caused by Stenocarpella maydis cause reduction in yield and quality of the maize due to the mycotoxins produced by the pathogen. Breeding for resistance is the most feasible option in managing ear rots. However, to obtain stable resistance to S. maydis has been a challenge partly due to effect of the environment and availability of different isolates. The objective of this research was therefore, to determine the effect of multiple isolate inoculations in breeding for resistance to S. maydis and to identify genotypes with stable resistance. Seven inbred lines were crosses in a 7 x 7 full diallel without reciprocals. The resultant crosses (21) and their parents (7) were planted and evaluated at two sites, Lusaka and Mpongwe, during the 2015/16 cropping season. The experiment was laid out as a randomized complete block design with 3 replications. Treatments were: (1) single inoculation with isolate A, (2) single inoculation with isolate B and (3) a multiple inoculation of two isolates AB and (4) control with no inoculation at all. The mean genotypic scores were found to be 5.52, 4.96, 5.50 and 1 for treatment 1, 2, 3 and 4 respectively. The t-test analysis revealed that treatment 1 had a higher mean disease severity score (5.52) as compared to treatment 2 (4.96) (P < 0.01). Equally mean for treatment 2 (4.96) and 3 (5.50) were significantly different (P < 0.01). However, there were no significant differences between mean disease severity score for treatment 1 and 3. This indicated that multiple isolate inoculations could give rise to inappropriate genetic information due to the possibility of antagonistic effect between isolates. The genotypes (P2 x P4) and (P3 x P6) crosses were found to have stable resistance to S. maydis. These exhibited consistent significant negative SCA effects (P< 0.05) in both locations

The timing of evaluation of genebank accessions and the effects of biotechnology:

The lack of ex-ante evaluation of germplasm in genebanks has been the single most prevalent and long-standing complaint of plant breeders about the management of genebanks. Advances in biotechnology offer the possibility of faster, cheaper, and more efficient evaluation methodologies. Will these new technologies favor ex-post evaluation, as some expect, or will it lead to more ex-ante evaluation? Will it also lead to earlier development of varieties with disease resistance traits in anticipation of actual infestations? Will the prospect of further advances in biotechnology favor delay of evaluation and development? This paper addresses these questions in the case of evaluation of germplasm for resistance to a disease.Gene banks, Plant., Biotechnology.,

Strawberry breeding for disease resistance in Dresden

Verticillium resistance is one of the most important breeding goals in strawberry resistance breeding at Dresden-Pillnitz. Resistance evaluation of cultivars, advanced selections and seedlings is realized under natural conditions at a provocation field and by artificial inoculation in the greenhouse. Introgression of Fragaria chiloensis L. (Miller) into Fragaria ×ananassa Duch. resulted in highly tolerant breeding selections. After back-crossing with cultivars of F. ×ananassa first genotypes were selected which can be evaluated in experimental cultivar trials at different locations in Germany

Mesoscopic Thermovoltage Measurement Design

Quantitative thermoelectric measurements in the mesoscopic regime require accurate knowledge of temperature, thermovoltage, and device energy scales. We consider the effect of a finite load resistance on thermovoltage measurements of InAs/InP heterostructure nanowires. Load resistance and ac attenuation distort the measured thermovoltage therefore complicating the evaluation of device performance. Understanding these effects improves experimental design and data interpretation.Comment: 2 pages, 3 figure

Evaluation of industrial platinum resistance thermometers

The calibration and stability of four surface temperature measuring industrial platinum resistance thermometers for use in the temperature range -120 C to 160 C was investigated. It was found that the calibration formulation of the International Practical Temperature Scale of 1968 provided the most accurate calibration. It was also found that all the resistance thermometers suffered from varying degrees of instability and hysteresis

The time evaluation of resistance probability of a closed community against to occupation in a Sznajd like model with synchronous updating: A numerical study

In the present paper, we have briefly reviewed Sznajd's sociophysics model and its variants, and also we have proposed a simple Sznajd like sociophysics model based on Ising spin system in order to explain the time evaluation of resistance probability of a closed community against to occupation. Using a numerical method, we have shown that time evaluation of resistance probability of community has a non-exponential character which decays as stretched exponential independent the number of soldiers in one dimensional model. Furthermore, it has been astonishingly found that our simple sociophysics model is belong to the same universality class with random walk process on the trapping space.Comment: 12 pages, 5 figures. Added a paragraph and 1 figure. To be published in International Journal of Modern Physics

The NASA Lewis Strain Gauge Laboratory: An update

Efforts continue in the development and evaluation of electrical resistance strain gauges of the thin film and small diameter wire type. Results obtained early in 1986 on some Chinese gauges and Kanthal A-1 gauges mounted on a Hastelloy-X substrate are presented. More recent efforts include: (1) the determination of the uncertainty in the ability to establish gauge factor, (2) the evaluation of sputtered gauges that were fabricated at Lewis, (3) an investigation of the efficacy of dual element temperature compensated gauges when using strain gauge alloys having large thermal coefficients of resistance, and (4) an evaluation of the practical methods of stabilizing gauges whose apparent strain is dependent on cooling rate (e.g., FeCrAl gauges)