油菜核不育两用系不育基因RAPD标记研究初报

为建立有效的不育基因分子标记辅助育种平台,以5个核不育两用系为研究材料,选用20条随机引物,利用RAPD混合集群分离分析法,对各两用系可育与不育基因池进行分子标记的初步分析.结果表明,在油研10号筛选到2个与不育基因相关的标记:BA2084-600和S1354-1300;在萝×诸中筛选到1个与不育基因相关的标记:LC02-500.在827AB、T18筛选到集团间有差异的引物,未筛选到通过集团单株检测的与其育性基因相关的标记.通过RAPD混合BSA法可以筛选到与不育基因相关的特异DNA标记.     

60Co-γ辐射诱导马铃薯表型变异效应的研究

为提高马铃薯品种费乌瑞它的变异频率,筛选新的变异类型,改良品种使其更加适应生产需要,对该品种的萌芽微型薯进行了6个60Co-γ辐照剂量处理[0(CK)、10、20、40、60、80 Gy],研究辐射当代(VM1)表型变异的效应。结果表明,60Co-γ射线处理能明显延缓薯块的出苗期,随着辐照剂量的增加,延缓效应逐渐增强;植株畸变率随着辐照剂量的增加而逐渐提高,80 Gy处理的植株畸变率达到100%;株高、单株叶片数及茎粗与辐照剂量仅在幼苗期存在显著负相关;单株产量在20~80 Gy辐照剂量范围与辐照剂量呈显著负相关,而10 Gy处理的单株产量显著高于CK和其他处理。认为:60Co-γ辐射对费乌瑞它微型薯VM1的生长具有明显的抑制效应,并导致植株性状出现不同程度的畸变,剂量越高畸变率越高、畸变类型越多;费乌瑞它的辐照剂量在20~40Gy范围较适宜。     

Flexible exchange of farming device data

A new trend in the farming business is to replace conventional farming devices with computerized farming devices. Accordingly, numerous computer-based farming devices for logging, processing and exchanging data have recently been installed on moving farm machinery such as tractors. The exchange of data generally takes place between the devices and farming systems, mostly installed at the premises of farmers, contractors, advisory services, etc. In most cases, data exchange is based on farming data exchange standards and is bi-directional. Bi-directional data exchange allows different devices and systems to exchange data based on a predefined set of rules. In consequence, many hand-coded data exchange solutions have been developed in the farming business. Although efforts regarding incorporating data exchange standards have been made, their actual usage so far has been limited, due to the fact that hand-coded bi-directional data exchange solutions have proven themselves too complex to maintain. Maintenance need to occur as requirements change frequently and the existing data exchange techniques lack flexibility with regards to efficient requirements change management. In addition, requirements change results in managing low-level code rather than a high-level specifications. This paper presents a bi-directional data exchange solution in the farming business that is based on high-level specifications without any need for hand-coding. The proposed solution supports ISOBUS based bi-directional data exchange as well as efficient requirements change management through a graphical user interface. The paper also demonstrates the use of the proposed solution based on a farming case study and open source technologies.     

The effect of simulated rat damage on irrigated rice yield and compensation

A field experiment was conducted to investigate the impact of simulated rat damage on grain yield in irrigated lowland rice in An Giang province, in the Mekong Delta of Vietnam. Rat damage was simulated by making a 45° cut at the base of the rice tillers about 3–5 cm above the soil surface. 0% (control), 5%, 10%, 25% and 50% of the tillers were removed at the tillering (25 days after sowing, DAS), panicle initiation (43 DAS), flowering (72 DAS) and ripening (87 DAS) stages. The total number of mature tillers, immature tillers and percent filled grains, the weight of 1000 grains and grain yields were recorded. The rice crop completely compensated by increased tillering and yield for tillers damaged up to 50% at the tillering stage. However, the damage and yield loss were highly variable. The ability of the rice crop to compensate at later stages progressively reduced. The implications for managing rat damage to rice crops are (1) rodent control activities should be applied before 10% of tillers are damaged at the tillering stage, and (2) a well balanced nitrogen supply during the tillering stage could potentially assist the rice plants to better compensate for rat damage.     

贵州省2008年油菜区试材料的SSR遗传多样性分析

为揭示油菜区试材料的亲缘关系,利用SSR分子标记技术分析了25份参加2007—2008年贵州省油菜区试材料的遗传多样性。结果表明:扩增出的115条带中45条呈现多态,多态性比率为39%。25份材料间的遗传相似系数在0.43~0.95,平均为0.69。在遗传相似系数0.63处分为3个类群,同一单位育出的材料往往优先聚为一类,遗传背景相近。     

马铃薯~(60)Co-γ辐射诱变突变体的分子鉴定

为了对马铃薯辐射诱变突变体的真实性提供分子证据,利用SRAP分子标记技术,对费乌瑞它及其辐射诱变突变体F0802、F0803-Ⅰ、F0803-Ⅱ和F0803-Ⅲ进行分子标记分析。结果表明,亲本与突变体间的遗传相似系数较高,都达到0.842以上;且聚类分析结果与4个突变体来源完全吻合。说明,从分子水平上确定了F0802、F0803-Ⅰ、F0803-Ⅱ和F0803-Ⅲ是费乌瑞它亲本的突变体;SRAP标记技术进行马铃薯辐射诱变突变体分子鉴定是可行的。     

马铃薯诱变育种研究进展

简述了诱变育种中常用的物理诱变、化学诱变和定点诱变的方法、原理,以及这些方法在马铃薯育种上的应用及研究概况,提出了马铃薯诱变育种存在的问题和对马铃薯诱变育种前景的展望。     

Landslide densities associated with rainfall,stand age,and topography on forested landscapes,southwestern Washington,USA

Elevated landslide rates in forested landscapes can adversely impact aquatic habitat and water quality and remove and/or degrade soil resources required for forest regeneration. As a result, understanding the associations between management actions, natural factors, and landslide rates is important information needed for land managers. An unusual and powerful storm in early December, 2007, caused record flooding and thousands of landslides across southwest Washington and northwest Oregon, USA, and provided a rare opportunity to examine the effects of both natural factors and forest management practices on landslide density. Landslide inventory data were collected from both aerial photos and systematic field surveys to provide a broad survey database that was used to develop estimates of landslide density and to examine associations between landslide density, precipitation, topography, and forest stand age across a 152,000 ha forested landscape in the Willapa Hills, Washington. We estimated the probability of detecting landslides on aerial photos for six strata defined by forest stand age and a broad range of rainfall intensity, expressed as percent of the 100-year, 24-h, maximum rainfall. Key findings are that landslide detection probability decreased with increasing stand age, but was similar across rainfall intensities. The overall fraction of field-detected landslides that were not detected on 1:12,000-scale aerial photos was 39%. Very few landslides occurred in the 0–100% of 100-year rainfall category, regardless of stand age or slope gradient class. At higher rainfall intensities, significantly higher landslide densities occurred on steep slopes (>70% gradient) compared to lower gradient slopes, as expected. Above ∼150% of 100-year rainfall, the density of landslides was ∼2–3 times larger in the 0–5 and 6–10 year stand age categories than in the 11–20, 21–30, 31–40, and 41+ categories. The effect of stand age was strongest at the highest rainfall intensities. Our results demonstrate that ground-based landslide inventory data are required in order to correct for detection bias from aerial photos, develop reasonable estimates of landslide density across environmental gradients such as rainfall magnitude and topography, and make unbiased interpretations of relationships between forest management associations and landslide occurrence.     

Biodegradation measurements confirm the predictive value of the O:C‐ratio for biochar recalcitrance

Suitable predictors of degradability are sought to support the identification of biochars with large potential to increase C sequestration in soils. We determined the biodegradation of 9 chars from hydrothermal carbonization and pyrolysis in two agricultural soils. The 200‐ and 115‐day degradation correlated strongly with the O:C‐ and slightly with the H:C‐atomic ratio of 9 and 14 biochars, respectively. Highest temperature treatment and ash content did not show similar correlations.     

Genetic analysis on body weight at different ages in broiler chicken raised in commercial environment

A multivariate model was developed and used to estimate genetic parameters of body weight (BW) at 1–6 weeks of age of broilers raised in a commercial environment. The development of model was based on the predictive ability of breeding values evaluated from a cross-validation procedure that relied on half-sib correlation. The multivariate model accounted for heterogeneous variances between sexes through standardization applied to male and female BWs differently. It was found that the direct additive genetic, permanent environmental maternal and residual variances for BW increased drastically as broilers aged. The drastic increase in variances over weeks of age was mainly due to scaling effects. The ratio of the permanent environmental maternal variance to phenotypic variance decreased gradually with increasing age. Heritability of BW traits ranged from 0.28 to 0.33 at different weeks of age. The direct genetic effects on consecutive weekly BWs had high genetic correlations (0.85–0.99), but the genetic correlations between early and late BWs were low (0.32–0.57). The difference in variance components between sexes increased with increasing age. In conclusion, the permanent environmental maternal effect on broiler chicken BW decreased with increasing age from weeks 1 to 6. Potential bias of the model that considered identical variances for sexes could be reduced when heterogeneous variances between sexes are accounted for in the model.