Quantitative genetics of rice II. A comparison of the efficiency of four breeding methods

A comparison of the efficiency of four breeding methods, the pedigree, modified pedigree and bulk methods, and single seed descent, with a pair of crosses whose potential was assessed in a previous paper, showed that, on average, the F₆ products of the three methods in which selection had been practiced outscored those produced by single seed descent for most characters for which improvement was sought. However, though the best lines produced by these methods achieved the desired targets for every character considered singly, none were significantly better than the best single seed descent line for any character in either cross. These results indicate that while it has been possible to practice effective negative selection during the course of inbreeding, by culling plants of poor performance, attempts to carry out positive selection of plants of superior performance were less successful. An audit of the costs incurred in producing the most promising F₆ lines that were extracted by these methods from each cross revealed that the single seed descent lines were the cheapest and those of the pedigree and modified pedigree methods the most expensive. These results indicate, therefore, that single seed descent is at least as effective as the other methods, is less costly and, where three generations can be raised per annum, is more rapid. Comparison of the observed proportions of superior single seed descent F₆ lines, with those predicted from information obtained from the F₃ generation of these crosses showed that for the majority of characters, the former were close to the latter. Single seed descent, therefore, has the further advantage that it is possible to predict the potential of a cross on information obtained from the early generations of the pedigree.     

Pressure,droplet size classification,and nozzle arrangement effects on coverage and droplet number density using air-inclusion dual fan nozzles for pesticide applications

Spray applications are most effective when they cover the greatest per unit area, improving target pest control. In order to optimize spray applications, nozzle companies have developed new designs that seek to provide the greatest and most uniform coverage per target unit area. While dual fan nozzles have been examined against single fan nozzles in several studies, there has not been a comprehensive comparison of multiple nominal flow rate and multiple dual fan nozzle types. This study sought to examine pressure, droplet size classification, and nozzle arrangement effects on droplet number density on horizontal artificial collectors using a fixed application rate. The relationship between coverage and nozzle type was significant (P < 0.001) as was the relationship between coverage and pressure (P < 0.001). The 207 kPa pressure resulted in the highest coverage for every nozzle type except the alternating TADFs (ATADF)s. The GAT 11003 resulted in the highest coverage overall with 39.6% at the 207 kPa pressure, followed by the TADF 11005 and TADF 11003 at 38.6% and 38.3% coverage respectively. The effect of pressure was significant for the droplet number density (P < 0.001) as was the effect on droplet number density from nozzle type (P < 0.001). The 414 kPa pressure resulted in the highest droplet number density for all nozzle types except the AITTJ 11003 and the MDD 11004. The GAT 11003 and GAT 11004 produced the highest overall droplet number densities with 73.0 and 72.6 droplets cm² at the 414 kPa pressure. The GAT 11003 had the greatest droplet number density at every pressure. Nozzle arrangement has a significant effect on spray coverage with asymmetric dual fan nozzles, and it would be recommended to alternate these nozzles on a spray boom to increase coverage especially at higher application speeds. Results from this study show that an applicator can select a coarser droplet size classification without observable loss in coverage, while greatly reducing the drift potential of the application.     

Evaluation of a spray nozzle patternator

Evaluation of a patternator for measuring lateral distribution of liquid from single nozzles or small booms is described. Liquid from the individual channels on the patternator table was collected in tubes and measured by weighing on an electronic balance, linked directly to a microcomputer. Considerable variation in pattern occurred between successive runs with individual nozzles: the coefficient of variation from seven different nozzles ranged from 3·27% to 9·15%; this may be caused by turbulence in liquid flow within the nozzle. The pattern obtained from sintered alumina nozzles was better than that with brass nozzles. The overall pattern from a boom was less variable than that obtained from single nozzles.     

Comparative performance of different-sized seed tubers derived from true potato seed

The growth and yield of plants from different-sized seed tubers derived from true potato seed were evaluated on a per stem, per plant, and per unit area basis using either single or multiple-sprout tubers. In single-sprout tubers, haulm dry weight per stem 47 days after planting was greater in the 40–60 g tubers when compared with that in the 5–10 g or the 10–20 g tubers. This resulted in greater tuber weight per stem in the 40–60 g tubers throughout the growing season. The number of tubers per stem was not affected by seed tuber size. In multiple-sprout seed tubers of increasing size, total tuber number and total tuber weight, as well as weight of those tubers larger than 45 mm, increased on a per plant basis but decreased on a per stem basis. At different rates of planting, 1–5 g seed tubers produced smaller tubers than 5–10 g or 10–20 g seed tubers. Increased rate of planting resulted in non-significant yield increases per unit area in plots planted with 1–5 g seed tubers. The yield increases were significant when 5–10 g and 10–20 g seed tubers were planted at higher rates. The number of main stems per unit of seed tuber weight was five times greater in 1–5 g tubers compared with that in 40–60 g tubers. This resulted in low seed weights per hectare when small tubers were planted and in a high ratio of harvested to planted tuber weight.     

Characteristics and classification of Japanese nozzles based on relative spray drift potential

European spray nozzle drift classifications have enabled the objective evaluation of the drift reduction performance of different nozzles with various operating parameters available in certain areas. The drift potential index reduction percentage (DIXRP) for one series of drift reduction nozzles used in Japan was investigated by wind tunnel tests. Based on the reference spray (Hypro ISO F110 03), most of the YAMAHO KIRINASHI ES nozzles had DIXRP values above 50% at nozzle heights from 0.3 m to 0.5 m, which means these nozzles can be considered as drift reduction nozzles. The best nozzle height range was found to be between 0.3 m and 0.4 m above the crop canopy. In addition, the DIXRP values were above 80% for a nozzle height of 0.3 m, except for one nozzle (the ES 05) which had the smallest droplet size and low flow rate which contributed to the large decrease in the DIXRP values when nozzle pressure increased. Large droplet diameter, high droplet velocity and low recommended nozzle height are considered to be important factors that can provide good drift reduction performance although droplet velocity was not measured in this study. The DIXRP value was inversely proportional to nozzle height. In addition, the influence of nozzle size on the DIXRP values was found to be statistically significant (P < 0.01), although the influence was not as obvious as that of nozzle height. Finally, a nozzle classification system for use in Japan based on the relative drift potential has been established.     

油菜的源库关系研究Ⅰ.角果大小对油菜后期源库的调节

试验于2001-2002年度在扬州大学实验农场进行.不同油菜品种后期的源库大小测定结果表明:(1)角果皮面积占油菜后期总光合面积的比例随角果的增大而直线增加,茎枝表面积所占的比例则随角果的增大而直线下降,果柄表面积所占的比例变化不大.(2)每角粒数随角果的增大呈先增后减的趋势,而单个籽粒的体积和每角籽粒总体积则随角果增大逐渐增大.(3)单位角果皮面积承担的籽粒数(SNPA)和单位角果皮面积承担的籽粒体积(SVPA)随角果增大而呈指数曲线下降.     

利用聚合酶链式反应技术研究单粒古代稻谷(公元800年)离体DNA片段的扩增

 在东南亚地区已发掘出很多古代稻谷，如果能从这些古稻谷中把DNA提出加以分析，可以得到有关栽培稻的系统分化和地理传播方面的直接信息。古代稻种的基因型相当复杂，必须要能从单粒种子开始分析，方能得到有价值的资料。为此，我们进行了从单粒古稻谷中提取DNA的研究工作。本研究采用通常提取植物组织中DNA的方法，从在日本挖掘出的古代稻谷单粒种子中提取出了50-100 ng左右的DNA片段。以这些DNA作为模扳，用聚合酶链式反应(Polymerase Chain Reaction，PCR)技术将DNA加以扩增．由其中几个DNA片段初步合成了相当于水稻光敏色素基因的DNA序列。     

利用聚合酶链式反应技术研究单粒古代稻谷(公元800年)离体DNA片段的扩增

在东南亚地区已发掘出很多古代稻谷,如果能从这些古稻谷中把DNA提出加以分析,可以得到有关栽培稻的系统分化和地理传播方面的直接信息。古代稻种的基因型相当复杂,必须要能从单粒种子开始分析,方能得到有价值的资料。为此,我们进行了从单粒古稻谷中提取DNA的研究工作。本研究采用通常提取植物组织中DNA的方法。从在日本挖掘出的古代稻谷单粒种子中提取出了50—100ng左右的DNA片段。以这些DNA作为模板,用聚合酶链式反应(Polymerase Chain Reaction,PCR)技术将DNA加以扩增。由其中几个DNA片段初步合成了相当于水稻光敏色素基因的DNA序列。     

Management of insect pests in celery and potato crops by pneumatic removal

Over the course of 4 years, five sets of trials were run in celery and potato crops to evaluate the efficacy of a field-scale vacuum (FSV) unit for use in insect pest management. The unit was designed to dislodge insects by blowing air from lateral vents onto the plants while simultaneously vacuuming from above. Efficacy was evaluated by field observations, yellow sticky traps and hand vacuum sampling before and after the FSV. All insects evaluated were effectively removed by the vacuum unit; typically, population reductions of 50–75% were achieved with whiteflies, leafhoppers, and aphids. In some trials, reductions were achieved that lasted from week to week. Additionally, agromyzid leafminers were significantly reduced in number, but population reductions were temporary because of their strong flying ability.     

Comparative performance of recycling tunnel and conventional sprayers using standard and drift-mitigating nozzles in dwarf apple orchards

The use of tunnel sprayers should be encouraged because they can potentially reduce pesticide input and drift in orchards. They could also allow smaller plot size in multifactorial trials in which fully randomized or randomized block designs are recommended. However, the effectiveness of plant protection products applied with tunnel sprayers cannot be reliably assessed without a thorough investigation into spray distribution in tree canopies. A set of three experiments was undertaken in an apple orchard to compare a new type of recycling tunnel sprayer with a standard axial fan sprayer, both of them fitted with either conventional hydraulic hollow cone nozzles (ATR) or drift-mitigating air induction cone nozzles (TVI). Its performance was assessed in terms of 1) spray deposit and coverage in the canopy, 2) sedimentation drift (spray drift to the ground) and 3) collection and recycling rate of the liquid sprayed in the tunnel. Artificial targets composed of cellulose papers and water-sensitive papers were used to evaluate the spray deposit and coverage at similar target positions for each treatment. A fluorescent dye was used as the spray tracer.     

Comparative effects of cut and treated seed tubers vs untreated whole seed tubers on seed decay, Rhizoctonia stem canker, growth, and yield of Russet Burbank Potatoes

Whole seed tubers have been reported to have performance advantages over seed tubers that have been cut, even if the cut tuber pieces are treated with a fungicide dust. For this study, whole seed tubers were compared to cut seedpieces and to cut seedpieces treated with four different commercial fungicide dusts for five consecutive seasons. A new field generation 3 Russet Burbank seed lot was used for each of the five years of this study. Both whole tubers and cut seedpieces were inoculated withFusarium spp., and the seedpieces were then treated with a fungicide dust. Inoculated and uninoculated untreated controls were also included. Emergence,Fusarium seed decay,Rhizoctonia stem canker, stem numbers, and vigor, as well as yield and grade data were obtained.Rhizoctonia stem canker in stems grown from whole seed tubers was significantly higher than in stems from seedpieces receiving fungicide treatment in several of the study years. Predicting whole seed tuber performance is difficult because performance varies more from year to year than performance of cut and treated seedpieces. Yield performance of whole seed tubers was not significantly better than cut and fungicide-treated seedpieces in any experimental year, and yield of large (over 280 g) tubers was significantly less than that recorded for two of the treatments when data from all five years were combined. This study demonstrated that untreated whole seed did not outperform cut and treated seedpieces for vigor, stem numbers, disease ratings, or yield in small plot comparisons for five consecutive seasons.     

Genetics of intra-gene pool and inter-gene pool hybridization for seed traits in common bean (Phaseolus vulgaris L.) germplasm from Europe

Due to adaptation to new ecological and manmade conditions, the large diversity evolved in the European common bean germplasm is of particular interest for plant breeding. The knowledge of the genetic relationships within and among races and gene pools and their performance per se will provide bean breeders with a starting point in designing crosses using contrasting and complementary parents to broaden the genetic base within the different commercial classes. A genetic study of seed size variation and protein markers in progeny derived from 16 intraracial, interracial and inter-gene pools European common bean populations was conducted. General and specific combining ability (GCA and SCA) values were significant for seed weight, indicating that both additive and nonadditive genetic effects were involved in conditioning seed weight. Interracial populations showed transgressive values due to the accumulation of large-seeded alleles. Genetic variation inside Andean germplasm, and Chile and Peru races in particular, exhibited useful genetic progress in these populations, providing lines with a large seed size, and so, an excellent market potential. The distribution of incompatibility between both gene pools (Mesoamerican and Andean) of the common bean was explored. Inter-gene pool populations provided lower means of inbred segregants than the mid-parent value. Therefore, a good option it would be select for large seed size according to a recurrent or congruity inbred-backcrossing selection programs. Analysis of allele markers frequencies in inter-gene populations showed segregation distortion with a higher than expected frequency of alleles from the Mesoamerican gene pool, many of which were fixed in the F₇ lines. The presence of a great percentage of markers that showed segregation distortion in these populations (87%) indicated that this phenomenon can be amplified by using distance related common bean genotypes. In addition, a high percentage of heterozygotes for the Phs locus (for the seed storage protein phaseolin) was found, which suggest that the Andean homozygous TT could not be expressed in Mesoamerican genetic background due to the action of some form of female specific mechanisms that affected gene exchange between parental germplasm in inter-gene pool populations. The present work provides useful information in the establishment of large seed size germplasm that could have a great deal of interest among breeders and may offer some possibilities to exploit existing variation within and between common bean races.     

花生种植技术的重大变革——单粒精播

传统花生种植穴播2粒或多粒,同穴多株之间地下部根系交错竞争肥水资源,地上部叶片遮挡竞争光热 资源,极易出现大小苗,限制花生产量进一步提高。山东省农业科学院花生栽培与生理生态创新团队根据竞争排 斥原理,建立了花生单粒精播高产栽培技术。单粒精播将花生每穴2粒或多粒播种改为每穴1粒,扩大株距,缓解 相邻植株间的竞争,个体均匀一致、整齐健壮,更能充分发挥单株生产潜力;单位面积株数减少,群体结构更加合 理,提高光合产物向荚果的分配率,通过提高经济系数来提高产量。本文论述了花生单粒精播技术的发展历程、理 论与技术突破、发展前景等,并提出了限制大面积推广的技术瓶颈,旨在推动该技术的大面积应用。     

玉米品种群的育种策略与应用

提出在新种子法实施和农业供给侧改革的形势下以及我国玉米生产季节面临气候条件多变和种业面临严重竞争压力前提下，玉米育种家和种子经营者应该根据不同玉米生态类型区、不同环境和市场的需求，在玉米育种过程中选育出满足不同市场需求的多元化品种组成优势互补的品种群，从而化解品种过于单一给玉米生产和企业带来的潜在风险，为品种多元化利用和玉米生产提供支撑。     

Effects of formulation on spray nozzle performance for applications from ground-based boom sprayers

The performance of agricultural spray nozzles has components relating to the droplet size and velocity distributions within the spray, spray structure, entrained air characteristics and the spray volume distribution pattern. The interaction of these physical performance parameters has been shown to influence target retention, efficacy and the risk of drift. Results from a number of studies have also shown that the physical properties of the spray liquid have a substantial effect on spray formation such that changes in formulation type can give changes in spray characteristics that would be equivalent to doubling the flow rate through conventional hydraulic flat fan nozzles. The interactions between the physical properties of the spray liquid and the characteristics of the spray formed is a function of nozzle design. However, analysis of a large data set for a range of types of hydraulic pressure nozzle has shown that sprays formed from liquids based on emulsions generally have a coarser droplet size distribution compared with sprays formed from surfactant solutions. Although some correlation between dynamic surface tension and viscosity with spray droplet size has been established, the results from work reviewed in this paper suggest that other factors also influence the spray formation process. Air induction and twin-fluid nozzles mix air and liquid in the spray formulation process to produce droplets with air inclusions. These nozzle designs have been found to have a performance that is more sensitive to changes in spray liquid properties compared with hydraulic pressure nozzles and to exhibit trends that are different from those of conventional nozzle types.     

Deposition characteristics and biological effectiveness of fungicides applied to winter wheat and the hazards of drift when using different types of hydraulic nozzles

Hydraulic-fan cone, low-pressure fan and two-chamber cone nozzles were used at 1.5, 3.0 and 6.0 bar (150, 300 and 600 kPa) to deliver 140, 200 and 3001 ha⁻¹ respectively of a fungicide spray to control mildew and yellow rust in winter wheat. No significant differences in biological effect were obtained although fan nozzles deposited significantly more on the upper parts of the stems, and two-chamber cone nozzles deposited less on the flag leaf and on the upper part of the stems. Because of their higher deposit and more even distribution, fan nozzles should be preferred, operated at a pressure of 1.5–3 bar to deliver a spray volume of 140–190 lha⁻¹ at 7 km h⁻¹ and to obtain an acceptable biological effect. Higher pressure (6 bar) and volume rates gave no improvement in fungicide performance. Adding a surfactant or penetration oil did not change the volume median diameter or proportion of spray liquid in droplets < 150 μm. Less drift was found when using two-chamber cone nozzles at 3 bar than with flat-fan spray nozzles at 1.5 bar. It is concluded that the two-chamber cone nozzle is useful for fungicide application when drift must be avoided.     

Outcrossing rate in cultivated autotetraploid potato

Outcrossing rates in potato were measured in an open-pollination field experiment at a location in the Peruvian Andes. Embryo spot, a dominant genetic seed marker, was used to measure outcrossing rate. The source of the dominant marker, the donor, was interplanted among recipient clones lacking the marker (recessive genotype), for which outcrossing was to be measured. Eight out of the 17 clones tested were advanced breeding clones which had wild species cytoplasm. Seven out of eight of these had outcrossing rates above 0.75, showing complete male sterility in one case and partial male sterility in six cases. Among the other clones tested, which were male-fertile, outcrossing estimates ranged from 0.10 to 0.74. Wide variability in outcrossing rate in autotetraploid potato suggests that it should be possible to select for higher outcrossing rate in production of open-pollinated true seed populations of potato for genetic or commercial purposes.     

Combining ability for main quality traits in peanut (Arachis hypogaea L.)

High-oleic peanuts has been recognized by processing sectors, seed sellers and consumers for their longer shelf life, longer seed life and mutiple healthe benefits. High oleate is becoming a requisite ​for varietal releases in many peanut breeding programs at present. To select desirable parents for high-oleic peanut breeding, the study was conducted to evaluate the combining ability of 5 high-oleic donors from our research team, based on quality of individual single seeds. General combining ability was significant for oleic, linoleic, stearic and palmitic acid, oil and protein, while specific combining ability was significant for the traits except oil. Among them, oil content was found to be conditioned solely by additive gene actions, and for other quality traits, additive gene effects were more important than non-additive gene effects. High-oleic CTW and normal-oleic Xiaojingsheng were selected as the best general combiners for peanut oleic acid improvement. Narrow-sense heritability was high for quality traits other than protein, suggesting that there was high potential for genetic improvement in these traits.     

Optimizing mechanical oil extraction of Jatropha curcas L. seeds with respect to press capacity, oil recovery and energy efficiency

The objective of this study was to optimize the mechanical oil extraction of Jatropha curcas seeds by increasing the efficiency of oil recovery and decreasing oil residues in press cake. The experiments were carried out with mechanical screw press type - Komet D85-1G. Four setups were created by parameter combination of two different screws (16 and 21.5 mm choke ring size), with two different press cylinders (1 and 1.5 mm bore size), three different nozzles (8, 10 and 12 mm nozzle diameter) and three rotational speeds (low, medium and high). Oil recovery reduced when rotational speed increases for all setups; highest oil was 89.4% (m/m). The oil recovery was increasing when energy input increased and decreasing when seed material throughput increased. The relations between energy input and seed material throughput followed a strict pattern, which correlated with oil recovery. This correlation can be used for determining the optimal operation parameters.     

Application of TOPSIS approach on parameters selection problem for rotor spinning machine

Classical statistical analysis has been generally used in obtaining optimum condition such as problems for rotor spinning machine. In these methods the preferences of the producer about yarn characteristics to achieve the desired end product properties have not been taken into consideration. However, machine parameters selection from possible alternatives with different performance levels about yarn quality is difficult task and is inherently a multi-criteria decision making problem. In the present study, valuable assistance in reaching acceptable solutions in order to select the appropriate doffing tube and its adjustment for 30 Ne rotor yarn spun to raise efficiency of weft knitting machine will be provided by technique for order preference by similarity ideal solution (TOPSIS) approach. In experimental part 30 Ne rotor yarn samples were spun by considering one quantitative variable, i.e., two different distances between the nozzle and rotor, and also two qualitative variables, i.e., nozzles in 4 different shapes and a draw-off tube with and without a torque stop. Then quality parameters of the yarns were analyzed with TOPSIS.