Use of rescue pollination to make a complex interspecific cross in potato

A cross between cultivated tetraploid potato and 2n-pollen producing triploid hybrids containingSolomon stoloniferum genomes was not successful using standard crossing procedures. Berry formation did not occur. Berries were formed, however, when pollination by the triploid hybrids was followed by application of cultivated tetraploid pollen. Berries contained seeds, most of which were intraspecific hybrids of 4x-4x origin. About 4% of 1749 seedlings scored with an isozyme marker were identified as interspecific hybrids of 4x-3x origin. The use of this second pollination is called “rescue pollination.” It appears to promote normal fruit development which standard crossing technique failed to do.     

棉花植物生长调节剂使用技术

在棉花的生育期使用植物生长调节剂,可以达到棉花高产优质的目的。通过详细介绍棉花常用的植物生长调节剂的类型、作用机理、增产效果、使用技术要点及注意事项,为棉花植物生长调节剂在生产中的应用提供参考。     

Small diameter Polyurethane vascular graft reinforced by elastic weft-knitted tubular fabric of polyester/spandex

Small diameter vascular grafts were fabricated from pure Polyurethane (PU) as well as PU reinforced with a tubular weft-knitted fabric. The tensile properties of the reinforced composite vascular grafts were compared with that of the tubular fabric itself and the pure PU vascular grafts. The elasticity and strength of the reinforced vascular grafts were improved compared with the tubular fabric. Strength of the reinforced vascular grafts was 5–10 times of the strength of the pure PU vascular grafts. Expanding the tubular fabric to increase the inner diameter of the reinforced vascular graft reduced the graft’s strength and initial modulus, but the difference was reduced as the PU content was increased. For grafts of the same inner diameter, increasing the PU content increased the thickness and strength of the graft wall, which led to a general increase in the strength and initial modulus of the composite vascular grafts.     

关于四川省抢播套作大豆、弥补夏旱损失的建议

根据<四川省气候灾害实时监测预警系统>监测,四川省五月底、六月初有89个县(市)发生了20～28 d的夏旱,其中60个县(市)夏旱仍在继续进行,主要分布在盆地中部和南部、川西高原西南部等地区.为此,对自贡、宜宾、内江、资阳等地区的旱情进行了实地考察.所到之地,正值玉米需水关键时期--抽雄期,由于干旱严重,大部分玉米株高不足两尺,下部叶片已经变黄,中上部叶片开始萎蔫.     

保护龙井茶产地生态环境 为西湖申遗添彩

本文阐述了生产西湖龙井茶优异的生态环境和人文历史,与西湖申遗的关系,对西湖龙井茶的生长现状进行了调研,分析存在的问题,并提出了保护西湖龙井茶产地生态环境,必须采取的措施。     

茶儿茶素的功效特性与开发利用探讨

茶儿茶素是茶叶中的主要功效成分。茶儿茶素在生物体内的吸收和分布情况,以及它们在体内进行的多种生物代谢过程,对茶儿茶素的功效有着重要影响。结合茶儿茶素在生物体内的作用机制和功效机理,开发利用茶儿茶素,将可能挖掘出茶儿茶素防御疾病的巨大潜力。     

Characterization of Palytoxin Binding to HaCaT Cells Using a Monoclonal Anti-Palytoxin Antibody

Palytoxin (PLTX) is the reference compound for a group of potent marine biotoxins, for which the molecular target is Na⁺/K⁺-ATPase. Indeed, ouabain (OUA), a potent blocker of the pump, is used to inhibit some PLTX effects in vitro. However, in an effort to explain incomplete inhibition of PLTX cytotoxicity, some studies suggest the possibility of two different binding sites on Na⁺/K⁺-ATPase. Hence, this study was performed to characterize PLTX binding to intact HaCaT keratinocytes and to investigate the ability of OUA to compete for this binding. PLTX binding to HaCaT cells was demonstrated by immunocytochemical analysis after 10 min exposure. An anti-PLTX monoclonal antibody-based ELISA showed that the binding was saturable and reversible, with a K_d of 3 × 10⁻¹⁰ M. However, kinetic experiments revealed that PLTX binding dissociation was incomplete, suggesting an additional, OUA-insensitive, PLTX binding site. Competitive experiments suggested that OUA acts as a negative allosteric modulator against high PLTX concentrations (0.3–1.0 × 10⁻⁷ M) and possibly as a non-competitive antagonist against low PLTX concentrations (0.1–3.0 × 10⁻⁹ M). Antagonism was supported by PLTX cytotoxicity inhibition at OUA concentrations that displaced PLTX binding (1 × 10⁻⁵ M). However, this inhibition was incomplete, supporting the existence of both OUA-sensitive and -insensitive PLTX binding sites.     

Rapid Screening of Potato Cultivars Tolerant to Nitrogen Deficiency Using a Hydroponic System

Increased cultivar tolerance to nitrogen (N) deficiency may increase productivity and reduce environmental impact of potato crops. In this study we screened 20 cultivars for the tolerance to N-deficient (0.05 mM nitrate) in comparison with N-abundant (7.5 mM nitrate) nitrate supply using plantlets grown for 15 days in a recirculating hydroponic system. Nitrogen deficiency increased the root-to-shoot ratio in 18 cultivars. Plant total dry weight (TDW) was reduced by an average of 61% under N-deficient nitrate supply. Tolerance to N deficiency was assessed as the TDW ratio (TDWR), calculated as the ratio of TDW under N-deficient to N-abundant nitrate supply. The cultivars Norland, Raritan, Nipigon and Langlade were significantly more tolerant to nitrogen deficiency (greater TDWR) than Eramosa, Carleton, and Epicure. The results indicate that the hydroponic system has capacity to rapidly screen a large number of cultivars for tolerance to N deficiency.     

Using the Gluten Peak Tester as a tool to measure physical properties of gluten

The functional properties of wheat are largely dictated by composition and interactions of the gluten proteins. All flours contain gliadin and glutenin, but produce baked products of varying quality, which provides evidence that gluten proteins from different wheats possess different properties. A common method to study differences in gluten properties, which is utilized in this study, is fractionation/reconstitution experiments to understand how various gliadin to glutenin ratios and how fractions from different wheat sources affect gluten aggregation properties. Gliadin and glutenin from a vital wheat gluten were fractionated with 70% ethanol and reconstituted at various gliadin to glutenin ratios. Gliadin and glutenin from a Canadian eastern soft, eastern hard and western hard wheat (14% moisture) were fractionated and substituted between flours at the native gliadin to glutenin ratio. Gluten combinations were evaluated with a Gluten Peak Tester at constant temperature and mixing. Varying gliadin to glutenin ratio showed that 50:50 is optimal for fast gluten aggregation while amount of glutenin dictates strength. Substitution experiments showed that replacing good quality gluten fractions with those from a lower quality wheat decreases gluten quality, and vice versa. Data also showed that cultivar specific differences in gliadin and glutenin are more important in dictating gluten strength (torque), while gliadin to glutenin ratio dictates aggregation time (PMT) independent of the source of fractions. The study demonstrated the ability of the improved method to evaluate gluten aggregation by controlling for all variables except the one being tested. The data also revealed information about gluten aggregation properties never before seen.     

Using the Gluten Peak Tester as a tool to measure physical properties of gluten

The functional properties of wheat are largely dictated by composition and interactions of the gluten proteins. All flours contain gliadin and glutenin, but produce baked products of varying quality, which provides evidence that gluten proteins from different wheats possess different properties. A common method to study differences in gluten properties, which is utilized in this study, is fractionation/reconstitution experiments to understand how various gliadin to glutenin ratios and how fractions from different wheat sources affect gluten aggregation properties. Gliadin and glutenin from a vital wheat gluten were fractionated with 70% ethanol and reconstituted at various gliadin to glutenin ratios. Gliadin and glutenin from a Canadian eastern soft, eastern hard and western hard wheat (14% moisture) were fractionated and substituted between flours at the native gliadin to glutenin ratio. Gluten combinations were evaluated with a Gluten Peak Tester at constant temperature and mixing. Varying gliadin to glutenin ratio showed that 50:50 is optimal for fast gluten aggregation while amount of glutenin dictates strength. Substitution experiments showed that replacing good quality gluten fractions with those from a lower quality wheat decreases gluten quality, and vice versa. Data also showed that cultivar specific differences in gliadin and glutenin are more important in dictating gluten strength (torque), while gliadin to glutenin ratio dictates aggregation time (PMT) independent of the source of fractions. The study demonstrated the ability of the improved method to evaluate gluten aggregation by controlling for all variables except the one being tested. The data also revealed information about gluten aggregation properties never before seen.     

An assay to quantify vascular colonization of potato byVerticillium dahliae

A procedure was developed and tested to evaluate potato germ plasm for relative rates of vascular colonization byVerticillium dahliae. The number of colony forming units (CFU) per ml of plant sap, extracted from stems and plated on a medium, was used to assess vascular colonization from plants grown for 100 days in a field plot infested withV. dahliae. Sap extracted from main stem tissue at the ground line gave more CFU ofV. dahliae than tissue at the mid and apical region of the main stem. Aliquots of 0.05, 0.1 and 0.2 ml of plant sap were equally efficient in measuring vascular colonization. Thirty-three clones were evaluated for amount of vascular colonization in field and greenhouse tests with the former giving the best results. Cultivars and clones resistant to Verticillium wilt in Idaho, Maine, Minnesota, North Dakota and New York each had a low index of wilt and a low number of CFU/ml ofV. dahliae in plant sap in these tests. Clones intermediate in both wilt index and vascular colonization as well as selections with a high wilt index and extensive vascular colonization were found using the fresh sap assay method. Correlation values of, r = 0.92, r = 0.91 and r = 0.86 were observed between CFU/ml and percentage of foliar wilt for 11 clones/cultivars in 1986, 1987 and 1988, respectively. The correlation between CFU/ml and both moisture and temperature for the cultivars Kennebec and Russet Burbank, during a 6-yr period was r = 0.83.     

A technique to estimate bird damage in wine grapes

Bird damage is a world-wide problem in agriculture. Measurement of such damage is an important first step in its effective management. We develop a visual assessment technique and a progressive sampling strategy using 5 strata and suggest sample sizes necessary to achieve an estimate of bird damage within a standard error of 5%. This strategy improved sampling efficiency by 67%, 79% and 80% compared to stratified systematic, standard systematic and random sampling. With an average cost of under $(AUS) 6 per block this technique is a rapid inexpensive method to estimate bird damage to vineyards and has application to most crop-bird situations.     

盐碱水稻田改植棉栽培技术

经试验研究．总结出天津盐碱水稻田改植棉的土壤和棉花生育特点及栽培技术。     

Effect evaluation of shotcrete vegetation mulching technique applied to steep concrete-face slopes on a highway of Taiwan

The Shotcrete Vegetation Mulching Technique (SVMT) was introduced to revegetate existing steep concrete-face slopes. By mixing cement and greening additives with hydraulic mulching materials in a particular proportion and directly spraying the mixture on steep concrete-face slopes, SVMT was proven to be superior to several traditional methods. SVMT can make a slope surface resistant to erosion within a short time (the uniaxial compressive strength of the slope was higher than 294.3 kN/m² on the 14th day), create an environment suitable for plant growth (the vegetation coverage rate on the 90th day was higher than 90%) and foster a plant community capable of natural succession (competition and succession among Bermudagrass, turf-type tall fescue, hairy beggarticks, chamber bitter, oriental false hawksbeard, American burnweed, Pacific Island silvergrass, and inchplant were observed), effectively improving wildlife habitat and increasing biodiversity (small arthropods were found on the site, including spiders, grasshoppers, ants, ladybirds, etc.). Furthermore, the ecological engineering effects of SVMT on the experiment site were evaluated according to Mitsch and Jørgensen’s 19 Ecological Design Principles. It was found that the site treated with SVMT conformed to principles 2, 3, 8, 10, 11, and 16.     

Evaluation of wildSolanum species for resistance to the US-8 genotype ofPhytophthora infestans utilizing a fine-screening technique

Greenhouse assays were carried out to characterizeSolanum accessions previously reported to be late blight resistant and to identify individuals within the accessions with high levels of resistance to late blight. Foliage of wildSolanum species accessions or hybrid cultivated potato x wild species (diploid or tetraploid) from Mexico, Russia, or South America was inoculated withPhytophthora infestans (US-8) and was scored for severity of foliar symptoms at 7 and 14 days after inoculation (DAI). Mexican accessions (S. brachycarpum,S. pinnatisectum,S. guerreroense, andS.fendleri) were significantly more resistant (1.1% infection at 14 DAI) than either Russian (59.1% infection at 14 DAI) or South American (53.4% infection at 14 DAI) accessions. Moreover, the genotypes within the Mexican accessions tended to be more uniformly resistant whereas genotypes within the Russian and South American accessions tended to segregate for resistance. The more resistant genotypes of Russian and South American accessions (176/546) were retested, and 56 genotypes were identified as having potential for use in potato breeding programs for resistance to late blight. Fifty percent of the selected genotypes were fromS. microdontum accessions PI498124, PI595510, and PI595511. The potential of these species for incorporation into breeding programs for late blight resistance is discussed.     

Soil quality responses to alfalfa watered with a field micro-catchment technique in the Loess Plateau of China

This paper explores the soil responses to alfalfa that is established using a field micro-catchment technique to harvest water under semiarid conditions. The field micro-catchment technique involved setting up ridges and furrows alternately on the flat land. The ridges served as the rainfall harvesting zone and the furrows as the planting zone. Five treatments were set up in this study: (1) conventional cultivation in a flat plot without mulch (CK), (2) plastic mulched ridge with 30 cm width of ridge and furrow (M30), (3) plastic mulched ridge with 60 cm width of ridge and furrow (M60), (4) bare ridge with 30 cm width of ridge and furrow (B30), (5) bare ridge with 60 cm width of ridge and furrow (B60). The mulching treatments increased the productivity of seeded alfalfa and significantly (p < 0.05) increased water use efficiency, causing the soil organic carbon (SOC), total soil nitrogen (TSN) and C/N ratio to increase. We also found that the alfalfa root system was very good at breaking up the plowing pan created by many years of tillage. In the M30 and M60 treatments, the total forage yield during the 3 years was higher than in CK by 10.7% and 40.3% respectively, whereas the total forage yield over the 3 years in the B30 and B60 treatments were lower than in the CK treatment by 14.2% and 28.3%, respectively. The water use efficiency in the mulching treatment was significantly higher than in the other treatments. After 3 years (2001–2003), the SOC content in ridge and furrow treatments (M30, M60, B30 and B60) was increased by 7.4%, 14.2%, 4.5% and 1.8%, respectively, contrasting with a decrease of 3.5% in the CK treatment. The increase in SOC positively correlated (R² = 0.6257) with the forage yield of alfalfa in the ridge and furrow treatments. The TSN for CK, M30, M60, B30 and B60 increased by 0.35%, 1.70%, 2.30%, 0.75% and 0.64%, respectively by the end of the 3 years. However, we found that the available phosphorus (P) in the mulch treatments during the 3-year period decreased rapidly indicating that it is necessary to apply P fertilizer to alfalfa-cultivated land under these management conditions. In conclusion, the ridge and furrow with mulch treatments, especially M60 treatments, proved to be a better pattern for alfalfa establishment, soil quality and nutrient cycling under semiarid conditions.     

Soilless production of potato minitubers using a hydroponic technique

Summary Potato minituber production is a classic way to multiply or acclimatize in vitro material before its use in the open field. This production is generally performed in a substrate of vegetable origin (based on peat) but it involves the risk of an infection by different pathogens present in the substrate, such asStreptomyces scabies (common scab),Spongospora subterranea (powdery scab), orErwinia spp. (bacterial soft rot). Another drawback associated with this system of production is its relatively high cost due to the initial cost of the in vitro material and the low multiplication rates. To solve these two problems, the Research Unit of Libramont (CRAGx, Libramont, Belgium) is developing a soilless production technique using clay balls as substrate, a recycled and disinfected nutritive solution as source of nutrients, and microtubers as in vitro starting material. With this technique (depending on variety), we have shown that a multiplication rate of 8 to 13 can be obtained, giving 470 to 760 minitubers per m² instead of a multiplication rate of 4 to 8 as observed in the controls (230 to 470 minitubers per m²). Multiplication rate may be improved even more with an adjustment of the composition of the nutrient solution. The quality of microtubers produced is excellent: no infections were observed and the physiological behaviour of these tubers is not different from the ones produced in the open field.     

茶叶加工中微波技术的系统应用

微能技术是一种利用电磁波、电磁场等物理微弱能量对食品、农产品的加工、贮藏进行处理的高效节能技术。本文探讨了微能技术在茶叶加工工程的初加工、深加工中的应用，主要包括微波通电加热技术、电磁蒸发干燥技术与微波萃取技术；分析了茶叶性质与技术处理效果的关系，及对微波机械性能设计的要求。     

地膜移栽棉简化栽培技术

近几年来，由于棉盲蝽发生较重，严重地影响了广大棉农植棉积极性。移栽地膜棉、露地移栽棉、直播地膜棉是目前主要栽培方式，其中移栽地膜棉兼有移栽棉和地膜棉的双重优势。为了降低生产成本、增加植棉效益，进行了移栽地膜棉优质、高产、简化配套技术探索，经过3年的试验示范认为，该技术省种、省膜、省工，实现了高产优质高效，较常规移栽地膜棉省工30％-40％，增产15％-20％，每公顷产籽棉4900kg左右。