论甘肃建成我国重要草类种子生产基地的可能与前景

通过分析国外草类种子生产概况、甘肃省草类种子的生产条件、生产现状、生产技术以及与国外的差距及发展前景,提出将甘肃建成美国俄勒岗州式的中国草类种子生产基地的建议,以及今后的工作重点和应用的技术措施,对指导甘肃牧草种子产业化升级具有重要的参考价值。     

Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

The system of rice intensification (SRI) is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons (2009-2011).In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting (CT) and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44) were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure (FYM);T 3,10 t/hm2 FYM+ 60 kg/hm2 N;T 4,5 t/hm2 FYM+ 90 kg/hm2 N;T 5,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.5 kg/hm2 blue green algae (BGA);T 6,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 (control,no NPK application) to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2-3 cm) was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management (INM) resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.     

Variability in cone and seed characteristics and seed testing in various provenances of Himalayan spruce (<Emphasis Type="Italic">Picea smithiana</Emphasis>)

We investigated the effect of provenance variation on cone and seed morphology and germination behaviour under different pre- treatments in Picea smithiana. Three categories of cones were recognized: large (13.18 cm × 3.30 cm 15.42 cm × 4.35 cm), medium (10.85 cm × 3.93 cm 12.18 cm × 3.98 cm) and small (7.69 cm × 3.06 10.98 cm× 3.39 cm). Significant variation was observed for various cone and seed characteristics. Seeds moisture content varied from 44.48% to 56.91%, seed size from 0.64 cm × 0.31 cm (largest seed) to 0.49 cm × 0.10 cm (smallest seed), and the seed weight from 2.45 g per 100 seeds to 1.36 g per 100 seeds on fresh weight basis of P. smithiana. The highest seed germination (72.0±7.53%) at 10°C was observed under chilling treatment in Tapovan provenance, while the minimum (15.0±5.71%) seed germina- tion was recorded at 25°C under control set in Tapovan provenance. Further among all the sources Pandukeshwar consistently had the highest average (38%) percent germination across all treatments. Compared to other temperature regimes and pretreatments, seeds subjected to 10°C and chilling treatment had the highest germination and took the least time for germination irrespective of provenance effects. Altitude (provenance) had little or no relationship with germination following laboratory treat- ments. Seeds from Tapovan provenance subjected at 10°C following chilling treatment may be suggested for further multiplication of this species.     

Effects of vegetation cover on recruitment of Ulmus pumila L. in Horqin Sandy Land,northeastern China

Understanding the effects of vegetation cover on seedling survival is helpful for promoting vegetation restoration in environmentally fragile zones. This study was conducted in the desertified, moving sand dunes of Horqin Sandy Land, Inner Mongolia, northeastern China. We hyphothesized that(1) seed density(i.e., number/m2) increases as vegetation cover increases, and(2) there will be more surviving seedlings in locations with higher vegetation covers. Total vegetation cover and initial densities of seeds, germinated seeds and surviving seedlings of Ulmus pumilia were evaluated under various vegetation covers in trying to clarify the effects of vegetation cover on the early stages of the plant life history. In agreement with the first hypothesis, initial seed densities were greater(P<0.05) under higher vegetation covers. The relationship between vegetation cover and initial seed density was represented by a quadratic regression, where a threshold occurred with a vegetation cover of 36%(P<0.05). The higher total vegetation covers, however, did not result in increased densities of germinated seeds(P>0.05), which on average represented 16.7% of initial seed densities. Even more, three months after the study initiation, total vegetation covers were similar(P>0.05) at all positions in the dunes, and they determined a similar number(P>0.05) of surviving seedlings at those positions(i.e. the second hypothesis had to be rejected). The mean number of seed- lings that survived at all positions was only 4.5% of germinated seeds. The number of surviving elm seedlings(0 to 1.7 seedlings/m2) under various vegetations covers(12.2% to 20.8%) at all dune positions by late summer would most likely not contribute to vegetation restoration in the study area.     

Mapping of three QTLs for seed setting and analysis on the candidate gene for qSS-1 in rice(Oryza sativa L.)

The lower seed setting is one of the major hindrances which face grain yield in rice.One of the main reasons to cause low spikelet fertility（seed setting）is male sterility or pollen abortion.Notably,pollen abortion has been frequently observed in advanced progenies of rice.In the present study,149 BC₂F₆ individuals with significant segregation in spikelet fertility were generated from the cross between N040212（indica）and Nipponbare（japonica）and used for primary gene mapping.Three QTLs,qSS-1,qSS-7 and qSS-9 at chromosomes 1,7 and 9,respectively,were found to be associated with seed setting.The recombinant analysis and the physical mapping information from publicly available resources exhibited that the qSS-1,qSS-7 and qSS-9 loci were mapped to an interval of 188,701 and 3741 kb,respectively.The seed setting responsible for QTL qSS-1 was further fine mapped to 93.5 kb by using BC₂F₇ population of 1 849 individuals.There are 16possible putative genes in this 93.5 kb region.Pollen vitality tests and artificial pollination indicated that the male gamete has abnormal pollen while the female gamete was normal.These data showed that low seed setting rate relative to qSS-1may be caused by abnormal pollen grains.These results will be useful for cloning,functional analysis of the target gene governing spikelet fertility（seed setting）and understanding the genetic bases of pollen sterility.     

Effect of spatial scale and topography on spatial heterogeneity of soil seed banks under grazing disturbance in a sandy grassland of Horqin Sand Land, Northern China

Soil seed banks play an important role in the distribution and composition of plant communities in semiarid grassland ecosystems.However,information on how spatial scale influences the spatial heterogeneity of soil seed banks in a grassland under grazing disturbance is still lacking.Based on field sampling and greenhouse germination,we measured the species composition and seed density of soil seed banks at different spatial scales (30 m×30 m,30 m×60 m and 30 m×90 m)along a topographical gradient in a sandy grassland in Horqin Sand Land, Northern China.By applying geostatistical methods,we examined how spatial scale and topography affected the spatial distribution of soil seed banks in the study area.Our results showed that the total number of species in soil seed banks,as well as the number of dominant annuals,increased with the increase of spatial scales.Seed density in soil seed banks decreased with the increase of spatial scales due to an increase in the slopes and relative heights of the sampling points.Geostatistical analysis showed that the relative structural variance(C/(C0+C))of seed density and species richness were over 65%for all spatial scales,indicating that these variables had an obvious spatial autocorrelation and the spatial structured variance accounted for the largest proportion of the total sample variance.Spatial autocorrelation of seed density in soil seed banks increased with the increase of measured scales,while that of species richness showed a reverse trend.These results suggest that the total number of species in soil seed banks is spatial scale dependent and lower topography may accommodate more seeds.Spatial distribution of seed density in soil seed banks is also scale dependent due to topographic variation.Grassland management,therefore,needs to consider local grazing disturbance regime,spatial scale and topography.     

Growth of ADP point seed crystal (100) surface

growth experiments of ammonium dihydrogen phosphate (ADP) point seed crystal were employed. And it is shown that the growth rate of (100) surface increases linearly with the increase of super saturation under the conditions of 0.005 kT/ωs~ 0.03 kT/ωs for phase transition drive force and 20~40 ℃ for the growth temperature. The growth rate of (100) surface increases exponentially with the rise of temperature when drive force is constant. The kinetics mechanism of crystal surface growth is in agreement with the screw dislocation growth under the condition of bulk diffusion transfer mechanism. There is death zone resulting from thermodynamic factors in crystal growth when the drive force is less than the critical value. The growth rate of (100) surface increases nonlinearly with increasing super saturation when drive force is within 0.05 kT/ωs~0.11 kT/ωs. The crystal growth is dominated by the 2D nucleation mechanism with the existence of other growth mechanisms.     

Effects of Ultra-drying on Viability and Physiological Characteristics of Platycladus orientalis Seed from Arid and Semiarid Areas of Northwest China

In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The seeds were dried from 6.8% to 5.1%, 4.4%, 3.7% and 2.2% MC, respectively, in a desiccator with the silica gel. The germination energy, germination percentage, germination index and vigor index of the seed were investigated. After ultra-drying, groups of seeds were carried on the accelerated agin...     

曲靖市种子管理体制改革的探索与实践

根据《种子法》和国务院办公厅《关于推进种子管理体制改革加强市场监管的意见》（国办发[2006]40号）及云南省人民政府办公厅云政办发[2006]174号、曲靖市人民政府曲政发[2006]119号等文件的精神,曲靖市9个县（市）区和市级种子管理体制改革工作任务按时完成,并取得较好的成绩,总体达到农业部农办发[2007]7号关于印发《种子管理体制改革验收方案》通知中的验收标准。