水稻不育系V20A幼苗蘖芽生长发育特性

水稻不育系V20A蘖芽分化发育可分为分化、定型、伸长和出生4个阶段，依不同节分蘖芽生长发育特性可分为3组，第一组是胚芽鞘，不完全叶节的分薛芽，第二组是第一、第二完全叶的分蘖芽，第三组是第三、第四、第五、第六、第七完全叶的分蘖芽。     

玉米种植模式生态经济效益研究

试验结果表明：“早玉米／红薯／晚玉米”的产量、产能、经济系数、经济效益、辅助转化效益、生态效益等均显优于“早玉米││早大豆－晚玉米”、“早玉米││花生／晚玉米”和“纯玉米－纯玉米”。     

冬虫夏草菌丝生长温度的研究

本文通过对青海省六个地区分离的冬虫夏草菌丝体生长温度的试验结果表明：冬虫夏草菌株在10、15、18、21、25℃5个温度梯度下以15℃下生长最快。可以认为冬虫夏草菌菌丝生长的最适平均温度为15℃。该菌丝生长最适温度应在15－18℃，其中以YSH－4菌株生长最快，由于供试的菌株生长的最适温度是各不相同的，在15、18、21℃各温度下均有其最适宜的菌株。     

Estimation of yield and dry matter of winter wheat using logistic model under different irrigation water regimes and nitrogen application rates

Complex simulation models need considerable input data that may be unavailable. In this study, based on growing degree days, a simple and empirical logistic model was used to predict top dry matter (DM) and grain yield (GY) of winter wheat in a semiarid area. For calibration and validation of the model, winter wheat cv. Shiraz was cultivated for two growing seasons (2009–2010 and 2010–2011) under different levels of irrigation water and nitrogen application rates. The coefficients of the logistic model and the harvest index were related to the seasonal amount of applied water (I) plus rainfall (R) and applied nitrogen plus residual soil mineral nitrogen (N + N_r) with good accuracy in 2009–2010. The values of DM were estimated using the developed empirical logistic model during the growing season in 2010–2011. Results also indicated that there was a good agreement between the measured and predicted GY in 2010–2011 with fair accuracy. Therefore, it is concluded that the presented model is appropriate for prediction of DM and GY of winter wheat at the study region.     

New Stably Expressed Loci Responsible for Panicle Angle Trait in Japonica Rice in Four Environments

Panicle angle (PA) of 254 recombinant inbred lines derived from a cross between two japonica varieties Xiushui 79 and C Bao was investigated under four environments,and a genetic linkage map including 111 SSR markers was constructed.Genetic analysis was conducted by mixed major gene plus polygene inheritance models,and quantitative trait loci (QTLs) identification by the QTLNetwork 2.0 and the composite interval mapping approach of WinQTLCart 2.5 software.Results showed that the PA trait was controlled by two major genes plus polygenes,mainly by major genes.Eight QTLs for PA were detected by the QTLNetwork 2.0 software,and each locus explained 0.01% to 39.89% of the phenotypic variation.Twelve QTLs for PA were detected by the WinQTLCart 2.5 software,with each locus explaining 2.83% to 30.60% of the phenotypic variation.Two major QTLs (qPA9.2 and qPA9.5) distributed between RM3700 and RM3600 and between RM5652 and RM410,respectively,and a moderate QTL (qPA9.7) distributed between RM257 and OSR28,were both detected by the two methods in all of the four environments.The negative effect alleles of the three QTLs were from Xiushui 79.In addition,eight pairs of epistatic QTLs with minor effects were also detected.QTL × environment interactions were not significant for additive QTLs and epistatic QTL pairs.     

Relationship between Phosphorus in Organic Growing Media and Its Uptake by Ryegrass

The supply of nutrients to plants from organic growing media depends on mineralization as the addition of inorganic nutrients is forbidden in certified organic systems. The objective of this study was to determine the relationship between total phosphorus (P), extractable (Olsen's) P, organic P, and biomass P in growing media and uptake of P by ryegrass. Three proprietary products were used alone and combined in 1:2 and 2:1 proportions to give nine growing media. Perennial ryegrass (Lolium perenne L. cv. ‘Choice’) was irrigated with a modified Hoagland's solution minus P, and the shoots were harvested after 28, 56, and 84 days. There was no significant correlation between the amounts of the different forms of P in the growing media and ryegrass dry weight or P concentration in harvested grass. However, total ryegrass P uptake was significantly positively correlated with initial total P and organic P in the growing media.     

Field-based evaluation of vernalization requirement,photoperiod response and earliness per se in bread wheat (Triticum aestivum L.)

Vernalization requirement, photoperiod response and earliness per se (EPS) of bread wheat cultivars are often determined using controlled environments. However, use of non-field conditions may reduce the applicability of results for predicting field performance as well as increase the cost of evaluations. This research was undertaken, therefore, to determine whether field experiments could replace controlled environment studies and provide accurate characterization of these three traits among winter wheat cultivars. Twenty-six cultivars were evaluated under field conditions using two natural photoperiod regimes (from different transplanting dates) and vernalization pre-treatments. Relative responses to vernalization (RRV_GDD) and photoperiod (RRP_GDD) were quantified using the reciprocal of thermal time to end of ear emergence, whereas earliness per se was estimated by calculating thermal time from seedling emergence until end of ear emergence for fully vernalized and lately planted material. An additional index based on final leaf numbers was also calculated to characterize response to vernalization (RRV_FLN). To test whether the obtained indices have predictive power, results were compared with cultivar parameters estimated for the CSM-Cropsim-CERES-Wheat model Version 4.0.2.0. For vernalization requirement, RRV_GDD was compared with the vernalization parameter P1V, for photoperiod (RRP_GDD), with P1D, and for earliness per se, EPS was compared with the sum of the component phase durations. Allowing for variation in EPS in the calibration improved the relation between observed versus simulated data substantially: correlations of RRP_GDD with P1D increased from r² = .34 (p < .01), to .82 (p < .001), and of RRV_GDD with P1V, from r² = .88 (p < .001), to .94 (p < .001). In comparisons of observed versus simulated anthesis dates for independent field experiments, the estimated model coefficients resulted in an r² of .98 (p < .001) and root mean square error of 1d. Overall, the results indicated that combining planting dates with vernalization pre-treatments can permit reliable, quantitative characterization of vernalization requirement, photoperiod response and EPS of wheat cultivars. Furthermore, emphasize the need for further study to clarify aspects that determine EPS, including whether measured EPS varies with temperature or other factors.     

试验预混料对肥育猪增重和肌肉品质影响的研究

试验选择24头“大长”仔猪,随机分为2组,即Ⅰ和Ⅱ组,进行3个阶段105 d的饲养对比试验。在试验基础日粮中,Ⅰ组添加1.5%的试验复合预混料A,Ⅱ组添加1.5%的市售复合预混料B作为对照,观察其增重效果和肌肉品质。试验结果表明,试验期Ⅰ、Ⅱ组肉猪的日增重分别为856和867 g,差异不显著（P>0.05）;平均料重比分别为3.19和3.15 ,差异不显著（P>0.05）;但肉质分析,Ⅰ组试猪中肌肉颜色、pH、大理石纹、嫩度、系水力和肌肉脂肪都分别优于对照组10.00%、3.68%、16.67%、9.38%、6.71%和13.07%,差异显著（P<0.05）;增重1 kg耗预混料成本分别为0.79元和0.72元,Ⅰ组比Ⅱ组高了9.7%,1头猪多耗费饲料成本5.60元,但该产品具有较大的应用前景。     

不同部位芽片对核桃方块形芽接成活及生长的影响

为改进栽培措施,提高核桃方块芽接成活率,用香玲核桃枝条不同芽位的芽片作试材,研究了不同部位接芽对核桃方块形芽接成活及生长的影响.结果表明:5月29日、6月5日和6月12日嫁接时,下部接芽的成活率分别为91.4%、91.8%和90.5%,中部接芽的成活率分别为97.9%、97.5%和95.5%,上部接芽的成活率分别为93.0%、94.7%和92.2%.嫁接成活率均为中部芽最高,可显著高于其他部位接芽,上部次之,下部最低.嫁接后第10、15、20 d,中部芽片的嫁接苗生长最快,上部次之,下部最慢.     

东北大豆品种生育期结构的初步分析

根据“东北地区大豆品种资源鉴定与评价”中的生育期资料,分析了东北大豆品种生育期结构的遗传变异,比较了不同结荚习性育成品种和地方品种生育期结构的区别。结果表明,东北大豆品种资源的生育期结构存在丰富的遗传变异。不同结荚习性的品种生育期结构有很大的差别。无限和亚有限型品种的生育期结构类似,生殖生长期较长,营养生长期相对较短,生育期比(R/V)相对较大。有限型品种的营养生长期较长,生殖生长期较短,生育期比明显小于无限和亚有限型品种。生育期和结荚习性相同的地方和育成品种相比较,育成品种的生殖生长期较长,营养生长期较短,生育期比较大,这种演变趋势在无限和亚有限品种上特别明显。辽、吉 黑三省的无限型育成品种营养生长期分别比地方品种缩短1.4,4.1和5.8天,生殖生长期延长1.1,1.5和1.4天,R/V值提高4.8,11.2和15.4％。吉、黑三省的亚有限有成品种的营养生长期平均较地方品种缩短了3.9和9.9天,生殖生长期延长了2.6和1.8天,生育期比提高了12.5和34.5％。有限型品种生育期结构的演变方向不明显。大豆育成品种生育期结构的演变是长期产量选择的间接效应。自觉地对生育期结构进行定向选择,有可能提高大豆产量的选择效率。