甜味物质应用进展及风险评价

随着生活水平的不断提高及营养健康理念的不断发展,人们逐渐开始关注糖摄入的问题,为了迎合减少热量摄入、预防肥胖的发展需求,越来越多用甜味剂代替糖的无热量、低热量、减糖、无糖产品出现在大众视野,而甜味剂作为实现这一需求的重要要素,对食品加工生产具有重要的意义。一直以来,人们认为甜味剂是安全无害、对人体不会产生负面影响,然而,随着不断的深入研究发现甜味剂并不是完全安全,其对人体健康或者加工生产会产生一定的危害。因此,为了更好地发展减糖趋势,必须清楚了解甜味剂带给身体的危害。按照使用场景的不同将甜味物质分为营养型甜味剂、非营养型甜味剂和填充型甜味剂三大类,并对其应用进展和风险危害进行综述,以期为食品工业的健康安全发展提供理论指导。     

通辽市气象因子对红薯产量的影响分析

研究通辽市气象因子对红薯种植产量的影响,旨在为通辽市农业种植结构调整提供科学依据。以红薯推广种植基地的种植资料和气象观测资料为基础数据,对气象因子与红薯产量的相关性进行分析。结果表明,积温、日照时数与红薯产量相关显著,相关系数分别为0.741和0.837,日平均气温和降水量与红薯产量未达到显著水平。除发根返青期外,其他发育期与全生育期的积温变化特征近似,相关系数均在0.788以上;日照时数年际变化与全生育期变化特征一致;仅薯块膨大期与全生育期降水量和日平均气温的年际变化相关显著,相关系数分别为0.933和0.936。热量和光照条件对产量影响相对较大,是红薯种植的限制因素,降水对产量影响不明显。     

不同类型粒用高粱生产力及光合能力的比较研究

本文以高粱籽粒高产为目的,采用适合于生产上的种植密度,对不同株高的粒用高粱品种、杂交种群体进行生产能力和逃命能力比较研究。研究结果表明,中秆杂交种具有最高收获指数,获得最高籽粒产量。但是,我国当前生产上种植的中秆杂交种都属于叶片宽长且平展的株型,在LAI较高的生育后期,群体过于郁蔽,透光通风不良,导致NAR     

Evapotranspiration predictions of CERES-Sorghum model in Southern Italy

The purpose of this study was to modify and calibrate the CERES-Sorghum water balance model for the dry, high radiation and windy conditions in an area in Southern Italy.

The equation for estimating potential evapotranspiration (E₀) was substituted by another one, calibrated in the study site and expressed as a function of equilibrium evaporation and maximum vapour pressure deficit (defined as the difference between the saturation vapour pressure at maximum and at minimum temperatures).

To calibrate the E₀ equation included in CERES-Sorghum, two drainage lysimeters, located at the Istituto Sperimentale Agronomico experimental farm, Foggia (Italy), were used to measure weekly evapotranspiration of well-watered, irrigated fescue grass, from 1976 to 1986.

A further drainage lysimeter, located in the same farm and cropped with well-watered grain sorghum (cv. NK 121) was used to calibrate the genetic coefficients input to the modified CERES-Sorghum model during the cropping seasons 1979 and 1980.

Simulated phenological dates (anthesis and maturity), grain yield, LAI, biomass and crop evapotranspiration were then compared with the measured ones in a fourth drainage lysimeter cropped with sorghum.

The modified model simulated grain yield accurately, but simulated daily evapotranspiration did not always match well the observed value, especially early in the crop cycle. Improvements are needed to the model in its simulation of soil evaporation and in the crop response function to temperature.     

湘南丘陵区红壤旱地红薯钾肥最佳用量与产量关系

为了寻求红薯的最佳钾肥施用量,提高钾肥利用率,笔者在湘南红壤丘陵区,设置钾肥5水平肥料效应田间试验,并采用田间试验和室内分析相结合的研究方法,分别测产,测定红薯养分含量以及土壤速效养分。试验结果表明:在钾肥施用量为225kg/hm2时,红薯的经济效益最高,每公顷的纯收入为9624.5元,增收率为47.7%,红薯的经济产量也较高,为19501.5kg/hm2,每公顷增产52.9%。同时,在该施肥水平下,整株红薯的氮、磷、钾养分吸收总量和钾肥利用率均最高,钾肥利用率达到15.6%。相反,在钾肥施用量为225kg/hm2时,0~20cm耕层土壤的速效养分含量和其他钾肥用量的处理相比较,均降低。综合考虑,在五个施钾水平中,笔者得出湘南丘陵区红薯钾肥的最佳施用量为225kg/hm2。     

双隐性甜糯玉米的主要农艺及品质性状

利用糯玉米(wxwx)分别与普甜玉米(su1su1)和超甜玉米(sh2sh2)杂交,在F1代的果穗上分离出纯合双隐性甜糯玉米(su1su1wxwx或sh2sh2wxwx),再同时种植双隐性甜糯玉米及亲本普甜玉米、超甜玉米和糯玉米,观测了一系列农艺性状,并分析了甜糯双隐性基因的互作效应.主要结果如下:(1)双隐性甜糯玉米的三叶期出现最迟,株高较高.(2)大部分     

樱桃透光和郁闭树冠相对光照强度及其果实品质和产量的差异

 以13年生‘红灯’甜樱桃（Prunus avium L.）为试材,应用树冠分格方法,研究了树冠透光和郁闭两种冠型内相对光照强度及其果实品质和产量的差异,以及相对光照强度与果实产量品质的关系。结果表明,两种树冠内相对光照强度均自下而上逐渐增高,透光和郁闭树冠小于30%的相对光照区域分别占树冠总体积的25.23%和52.78%。透光树冠果实分布均匀,主要集中在树冠1.5～2.5 m的高度;而郁闭树冠果实分布差异较大,主要在树冠的外围和上部;产量分别是9.02t.hm-2和3.53t.hm-2。果实品质因素与相对光照强度的回归分析表明樱桃单果质量、果实硬度、果实可溶性固形物含量、可滴定酸含量、固酸比最佳的相对光照强度值分别为76.52%、46.84%、100.00%、41.63%和75.77%。     

第8届国际甜椒圃地试验报告

从6个方面对参试品种进行了比较分析,结论认为：除ISPN8#3在陕西岐山试验地表现差以外,其余品种（系）均表现优良。     

S‐locus diversity and cross‐compatibility of wild Prunus avium for timber breeding

Prunus avium is primarily cultivated for its fruit, sweet cherries. However, it is also used to produce high‐quality timber. In a P. avium seed orchard, gametophytic self‐incompatibility is a restriction for free pollen flow and should be considered when establishing basic forest materials. In this study, S‐locus diversity and cross‐incompatibility of wild cherry individuals in clonal banks established for breeding for timber production were investigated. Wild cherry trees (140) with outstanding forest growth habit, collected in northern Spain, grafted and planted in two clonal banks, were genotyped at the S‐locus. The self‐incompatibility S‐locus genes, S‐RNase and SFB, were analysed by PCR. Twenty‐two S‐haplotypes, resulting in 72 different S‐genotypes, were identified. The genotypes were grouped into 33 incompatibility groups and 39 unique genotypes. This initial S‐locus analysis revealed large genetic diversity of wild cherry trees from the Spanish northern deciduous forest, and provides useful information for seed orchard design. Wild P. avium displays significantly more genetic diversity than what is detected in local cultivars, revealing a narrowing of genetic diversity during local domestication.     

优质甜橙新品种‘津香橙’

 ‘津香橙’是由‘梨橙’（母本）与‘强德勒红心柚’（父本）杂交培育出的优质无核甜橙新品种。果实近圆球形,单果质量150 ~ 160 g,种子数0.6粒以下;果面光滑,深橙色,油胞细密;果肉细嫩化渣,酸甜适中,风味浓郁,可溶性固形物含量13.1%,总酸9.6 mg · mL^-1,总糖102.6 mg · mL^-1,维生素C含量468 mg · L^-1,可食率70.7%,出汁率57.3%。树势强健,丰产性好,在10年‘梨橙’中间砧上高接换头第3年株产达到40.58 kg。成熟期在11月下旬。适宜重庆及相似生态区年均温17.5 ℃以上区域种植。