Is backcrossing a good strategy for improving elite lines for quantitative traits in general? Results reported here demonstrate the effectiveness of a backcrossing program for improving quantitatively inherited disease resistance traits, which are strongly influenced by the environment. Through backcross breeding, we were able to improve an important commercial inbred line, FR1064, for ear rot and fumonisin contamination resistance without significantly lowering its yield potential, even with the use of a donor line with poor agronomic potential. Following one generation of selection on advanced backcross-derived lines, gains were observed for the primary trait of interest in advanced inbred generations. Following two generations of selection, we improved potential performance for ear rot resistance and reduced fumonisin accumulation in the 19 selected lines without significantly affecting important agronomic characteristics such as plant height, ear height, or flowering time compared to the recurrent parent, FR1064. The 19 selected lines were also significantly more resistant to ear rot under inoculated conditions than the FR1064 topcross without exhibiting significant reductions in topcross grain yield or other agronomic traits. Several individual lines were identified that were not statistically different from GE440 for ear rot or fumonisin content as inbreds or from the GE440 topcross for ear rot. These lines exhibited topcross yields comparable to the FR1064 topcross, although they were not competitive with commercial check yields. Thus, from a practical standpoint, the backcrossing method was effective at improving quantitative disease resistance in an elite commercial line using an unadapted donor parent. We also genotyped selected lines at DNA markers linked to ear rot and fumonisin resistance quantitative trait loci (QTL) identified in the BC1 generation of this cross to determine which QTL demonstrated allele frequency shifts due to selection.

Use of public tropical lines for U.S. commercial maize (Zea mays L.) breeding is either undocumented or non-existent. A possible exception is the old Cuban line A6, which was still being used in tropical hybrids over 40 years after its development. A major reason for the under-utilization of this valuable germplasm source is the sparse amount of yield-trial data available for most tropical lines. Effective evaluation of tropical, unadapted maize is costly and time-consuming in the U.S. corn-belt, where most temperate maize breeding is done. Thus, temperate maize breeding programs have shown minimal interest in such lines. The narrowness of the temperate maize (Zea mays L.) germplasm base has long been recognized, and there are many available, elite tropical lines that might be used to profitably broaden it. However, there are few comparative yield-trial data by which to choose which line(s) might be most useful. As the investment required for using a tropical line in a temperate breeding program is large, line-choice is critical. Tropical maize (Zea mays L.) represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. The objective of this study was to integrate candidate gene analyses with photoperiod QTL mapping across multiple maize populations. We tested the hypothesis that diverse tropical inbreds carry alleles with similar effects at four key photoperiod response quantitative trait loci (QTL) previously identified in maize. Four tropical maize inbreds were each crossed and backcrossed twice to the temperate recurrent parent B73 to establish four sets of introgression lines. Evaluation of these lines under long day lengths demonstrated that all four QTL have significant effects on flowering time or height in these lines, but the functional allelic effects varied substantially across the tropical donor lines. At the most important photoperiod response QTL on chromosome 10, one tropical line allele even promoted earlier flowering relative to the B73 allele. Significant allelic effect differences among tropical founders were also demonstrated directly in an F2 population derived from the cross of Ki14 and CML254. The chromosome 10 photoperiod response QTL position was validated in a set of heterogeneous inbred families evaluated in field tests and in controlled environments.

Is backcrossing a good strategy for improving elite lines for quantitative traits in general? Results reported here demonstrate the effectiveness of a backcrossing program for improving quantitatively inherited disease resistance traits, which are strongly influenced by the environment. Through backcross breeding, we were able to improve an important commercial inbred line, FR1064, for ear rot and fumonisin contamination resistance without significantly lowering its yield potential, even with the use of a donor line with poor agronomic potential. Following one generation of selection on advanced backcross-derived lines, gains were observed for the primary trait of interest in advanced inbred generations. Following two generations of selection, we improved potential performance for ear rot resistance and reduced fumonisin accumulation in the 19 selected lines without significantly affecting important agronomic characteristics such as plant height, ear height, or flowering time compared to the recurrent parent, FR1064. The 19 selected lines were also significantly more resistant to ear rot under inoculated conditions than the FR1064 topcross without exhibiting significant reductions in topcross grain yield or other agronomic traits. Several individual lines were identified that were not statistically different from GE440 for ear rot or fumonisin content as inbreds or from the GE440 topcross for ear rot. These lines exhibited topcross yields comparable to the FR1064 topcross, although they were not competitive with commercial check yields. Thus, from a practical standpoint, the backcrossing method was effective at improving quantitative disease resistance in an elite commercial line using an unadapted donor parent. We also genotyped selected lines at DNA markers linked to ear rot and fumonisin resistance quantitative trait loci (QTL) identified in the BC1 generation of this cross to determine which QTL demonstrated allele frequency shifts due to selection.

Optical interferometry and polarimetry have separately provided new insights into stellar astronomy, especially in thefields of fundamental parameters and atmospheric models. We present: scientific justifications for “full-Stokes” opticalinterferometric polarimetry (OIP); updated instrument requirements; preliminary beam combiner designs; polarimeterdesign; end-to-end OIP data reduction; and realistic reimaged full-Stokes models of Be stars with a suitable number oftelescopes plus noise sources. All of this work represents preliminary research to construct an OIP beam combiner.

When paprika is cultivated during summer season, thrips starts to occur in the early growing season and reaches its peak in late June. In the treatment using Orius laevigatus and Neoseiulus cucumeris, natural enemies to thrips, thrips density was 87.6/trap and 51.31trap on June 23. After Orius laevigatus and Neoseiulus cucumeris were treated twice on June 24 and July 23, the number decreased considerably. On August 23, it was 36.9/trap and 40.3/trap and from the mid August to early September thrips density remained low. Effect of Orius laevigatus and Neoseiulus cucumeris on suppression of thrips density was 35.7% and 44.6% on July 22, however, the number went up to 88.8% and 80.5% on September 3.

Investigation on oriental melon was carried out for 30 minutes starting at 7 PM every day from March 21 to May 24 to find out the effect of light emitting diode on seedling quality, grafting, growth and flowering of oriental melon. According to the result of the investigation, plant height was longer in Blue, Infrared, Red+Blue and Red treatment and leaf number was higher in Blue, Red+Blue and Infrared treatment than those of control. No big difference was identified between control and Yellow, Green, Ultraviolet treatments. Grafting rate was high in Green, Red+Blue and Green treatment. The number of flower evef}' week in control was nine, the number was almost 1 higher in White and Ultraviolet A treatments, but it was 1 to 4 lower in the rest of treatments. The number of female flowers of control was 10, however, it was 21 in Infrared treatment, 17 in White, 15 in Ultraviolet, 13 in Red+lnfrared, 12 in Blue and Red+Blue, 11 in Yellow and 8 in Green.

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

FThe aim of this study was to carry out a preliminary test of the air quality modelling system (HIRES- AIRCHEM) developed at The University of New South Wales, particularly with regard to the forecast ozone distribution. This was achieved by assimilating the New South Wales State Environment Protection Authority (EPA) emissions inventory, consisting of road and non-road sources, and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA’s goal of 8pphm on several occasions. The model forecasts of ozone distribution verified well with the EPA’s ozone readings. This result has important implications for possible future use of the system as a tool for routinely predicting and assessing air quality.