向日葵不定根的研究——向日葵不定根的形态结构

向日葵除了由种子的胚根长成的主根及其侧根外,还能够自胚轴处再长出不定根。到开花期不定根总量已超过自主根上发出的侧根的重量,以后还在继续增加。向日葵的主根及其侧根的初生结构为典型的4原型,导管发育较迟,而不定根则为6原型,主要是受到胚轴结构的影响,根与胚轴的结构很协调。从不定根的结构特点导致吸收功能等较主根侧根强盛,表现出结构与功能的一致性。     

Benchmarking sunflower water productivity in semiarid environments

Appropriate benchmarking is essential for evaluating the efficiency with which crops use water and for identifying constraints, other than water, to crop yield. No benchmark exists for sunflower. Boundary and simulation analyses were used to quantify the water productivity of sunflower crops grown in the Western Pampas (semiarid central Argentina). The approach involved the use of a large database (n = 169) collected in farmers’ fields over a period of 4 years, and the application of a crop simulation model in combination with actual weather and soil data. Using field data, an upper bound of 8 kg grain ha⁻¹ mm⁻¹ for water productivity, with an apparent seasonal soil evaporation of 75 mm, was defined. Seasonal water supply exceeded maximum expected seasonal crop requirements (ca. 630 mm) for many crops, and a majority of crops with <630 mm of available water during the season had water productivities considerably lower than the upper bound. The field data-based upper bound was indistinguishable from that obtained using yields for a set of 47 simulations using observed initial values for soil water and nitrogen profiles. Simulation confirmed the main features of the boundary-analysis applied to field data, and many simulated crops had yields that fell below the boundary function, even when simulated yield was plotted against simulated seasonal evapotranspiration or transpiration. Long-term (33-year) simulation analyses for two sites showed that most sunflower crops in the area are subjected to episodes of transient and unavoidable water stress after floral initiation. High levels of available soil water at sowing moderate, but in most years do not eliminate, these exposures to water stress. Yield gaps with respect to the boundary function were associated with deficient or excessive rainfall during grain filling, and other, non-water related, factors such as inadequate crop nutrition, biotic stresses, low photothermal quotients during the interval close to anthesis, and lodging. A grain yield/seasonal evapotranspiration plot for a large (n = 154) data set from experiments conducted by others in five separate environments suggests that the boundary function found for the Western Pampas is broadly applicable. Sunflower water productivity, corrected for oil-synthesis costs and seasonal vapour pressure deficit differences, approximates that of winter cereals grown in Mediterranean environments.     

Increasing water productivity of irrigated crops under limited water supply at field scale

Borkhar district is located in an arid to semi-arid region in Iran and regularly faces widespread drought. Given current water scarcity, the limited available water should be used as efficient and productive as possible. To explore on-farm strategies which result in higher economic gains and water productivity (WP), a physically based agrohydrological model, Soil Water Atmosphere Plant (SWAP), was calibrated and validated using intensive measured data at eight selected farmer fields (wheat, fodder maize, sunflower and sugar beet) in the Borkhar district, Iran during the agricultural year 2004-2005. The WP values for the main crops were computed using the SWAP simulated water balance components, i.e. transpiration T, evapotranspiration ET, irrigation I, and the marketable yield Y_M in terms in terms of Y_MT⁻¹, Y_M ET⁻¹ and Y_M I⁻¹.The average WP, expressed as $ T⁻¹ (US $ m⁻³) was 0.19 for wheat, 0.5 for fodder maize, 0.06 for sunflower and 0.38 for sugar beet. This indicated that fodder maize provides the highest economic benefit in the Borkhar irrigation district. Soil evaporation caused the average WP values, expressed as Y_M ET⁻¹ (kg m⁻³), to be significantly lower than the average WP, expressed as Y_MT⁻¹, i.e. about 27% for wheat, 11% for fodder maize, 12% for sunflower and 0.18 for sugar beet. Furthermore, due to percolation from root zone and stored moisture content in the root zone, the average WP values, expressed as Y_MI⁻¹ (kg m⁻³), had a 24-42% reduction as compared with WP, expressed as Y_M ET⁻¹.The results indicated that during the limited water supply period, on-farm strategies like deficit irrigation scheduling and reduction of the cultivated area can result in higher economic gains. Improved irrigation practices in terms of irrigation timing and amount, increased WP in terms of Y_MI⁻¹ (kg m⁻³) by a factor of 1.5 for wheat and maize, 1.3 for sunflower and 1.1 for sugar beet. Under water shortage conditions, reduction of the cultivated area yielded higher water productivity values as compared to deficit irrigation.     

缩节胺、多效唑和矮壮素对向日葵生理特性的影响

为使用化控技术塑造合理株型,通过不同浓度缩节胺、多效唑和矮壮素对食用向日葵生理特性分析,研究植物调节剂对向日葵生理特性影响以及合理的施用量。以新食葵7号为材料,将喷施缩节胺、多效唑和矮壮素设置5个不同处理浓度,研究不同浓度的植物生长调节剂下向日葵叶绿素、游离脯氨酸和可溶性蛋白含量、膜脂过氧化以及保护性酶活性的变化规律。不同浓度植物生长调节剂对向日葵的各生理指标影响不同,缩节胺200mg/L、多效唑100mg/L和矮壮素12g/L提高向日葵叶片的叶绿素和可溶性蛋白含量、增加游离氨基酸的积累量、降低丙二醛的产生、增强SOD、POD、CAT保护酶活性,提高植株的生理代谢功能。     

轮作及农艺措施对减轻向日葵列当危害的影响

向日葵列当对向日葵生产带来严重危害,目前向日葵生产中主要通过化学除草、选择抗性品种进行防除。通过合理轮作是减轻列当危害的有效手段,但是如何选择轮作作物、其防除效果如何并不清晰。采用向日葵连作重茬土壤进行盆栽试验,并进行田间调查,研究结果表明：向日葵与燕麦、小麦和马铃薯轮作均可不同程度地降低向日葵列当寄生率,其中向日葵—燕麦—向日葵轮作对列当耗减最多,与对照组（向日葵连作）相比列当寄生率降低30%。向日葵—燕麦—向日葵—燕麦—向日葵、向日葵—小麦—向日葵—小麦—向日葵轮作列当寄生率均低于50%,两者差异不显著,而显著低于向日葵—马铃薯—向日葵—马铃薯—向日葵轮作处理。田间调查结果显示向日葵的花盘直径与列当寄生数呈负相关,地膜覆盖对向日葵列当寄生影响不大。综合得出,燕麦是一种良好的向日葵列当诱捕作物,适合在内蒙古等食用向日葵主产区推广应用。     

向日葵自交系一年三代的加代繁育技术探析

为了获得向日葵自交系一年三代的繁育技术,缩短向日葵自交系的选育进程,利用向日葵本身作物特性及向日葵自交系日前研究现状,以向日葵大田繁育种植为基准,进行了海南加代繁育研究.结果表明:向日葵自交系每年可繁育三代,每一代能够完全成熟所需的≥5℃的有效积温为1 900℃以上、,加代繁殖地点为海南三亚.以此作为繁育三代的技术核心保证,建立起向日葵自交系一年三代的繁育方法,加速了选育进程,降低了选育成本.     

几个国外引进向日葵自交系育种应用价值的初步评价

本试验对利用引进的9个国外向日葵自交系所配的组合进行了田间鉴定。研究表明，新组合中出现了几个在生产力水平上超过当地最新育成的杂交种的优良组合，最优组合的子实产量达3756kg/hm^2，产油量达1834．95kg/hm^2。引进国外种质资源，积极开发创新并应用，是我国向日葵新品种选育的有效途径之一。     

单层浸渍纸贴面葵花秆刨花板的研究

本文论述了葵花秆刨花板的生产工艺、产品性能，分析了单层浸渍纸贴面用基材板的性能，并与国家标准进行了比较，填补了几项指标要求。研究中对国产刨花板设备及其生产工艺进行了调整，生产出了符合单层浸渍纸贴面板性能要求的基材板，同时研制了改性三聚氰胺树脂胶、改性脲醛树脂胶，制定了单层浸渍纸贴面工艺，贴面板各项性能达到国家标准。     

Effect of morphological traits of plant, head and seed of sunflower hybrids on house sparrow damage rate

Birds are important key pests of sunflower crops in many countries. In this study, 615 heads and 5429 seeds of 31 sunflower hybrids (single cross, three-way cross and introduced hybrids) were randomly selected and rates of bird damage were estimated at the Plant Breeding Research Institute of Karaj during the summer of 2004-2005. The Spearman correlation test showed a significant relationship between bird damage rate and some plant characteristics such as height of plant head above the ground (r = 0.100), inter-head distance or distance of heads from stems (r = −0.195), distance of petiole (nearest leaf) from head (cm) (r = −0.113), head diameter (r = −0.213), head angle to the horizon (r = 0.217) and seed density in sunflower heads (r = 0.320) (p < 0.01), but there was no significant correlation between bract length (r = 0.047), the sterile area to head surface ratio (r = −0.020), achene length (r = 0.267) and hull thickness (r = −0.002) and the rate of bird damage (p > 0.05). The Kruskal-Wallis non-parametric test showed significant differences of bird damage rate to hybrid plants, for head shapes, bract orientation in relation to the head surface and achene colors (p < 0.01) but no significant for stem hanging forms and degree of striping on the achene (p > 0.05). In conclusion, the sunflower heads suffering lower bird damage rates had traits such as greater diameter, flat and convex shape (edges curled outside), fewer angles to the horizon, more down-faced heads, open and longer bracts, longer distances between adjacent stems or heads, longer distance of petiole from head, and lower seed density. In considering the results of the present and previous studies, there was a degree of inconsistency of findings across all studies, but not for each sunflower trait. Future studies are still necessary for height of head above the ground surface, stem hanging form, head shape, bract length and orientation, sterile area ratio, seed density, achene length, color and striping, and hull thickness. Nevertheless, plant breeding trials should bear in mind these results to pursue the understanding of relevant characteristics in morpho-genetic studies in relation to bird damage.     

向日葵未成熟胚培养中不定芽的发生

研究了向日葵未成熟胚培养中不定芽的发生情况,结果表明,向日葵子叶(?)未成熟胚再生不定芽的能力很强,下胚轴较子叶容易产生不定芽;基因型和培养基是影响不定芽再生频率的重要因子.基因型不同,其不定芽的再生频率差异很大.本实验中大多数基因型都能诱导出不定芽.再生频率在40%以上.最高的达91%.自交系、杂一代和保持系的再生频率高于普通品种.培养基中高含量蔗糖及适宜的6—BA含量有利于不定芽的发生.由不定芽培育出的绿苗在温室条件下,大部分可以正常开花结实.