Characterization and Selection of Phosphorus Deficiency Tolerant Rice Genotypes in Sri Lanka

Phosphorus（P） deficiency in soil is a major constrain for rice production. An important set of rice genotypes（landraces, old improved and new improved varieties） were screened for P deficiency tolerance in two major cropping seasons of Sri Lanka, in 2012. The Ultisol soil, which was collected from a plot cultivated with rice without fertilizer application for past 40 years（P₀） at the Rice Research and Development Institute（RRDI）, Bathalagoda, Sri Lanka, was used as the potting medium for greenhouse trials. Two field trials were conducted in the same plots at RRDI. Both P₀ and P₃₀（30 mg/kg P₂O₅） conditions were used in the two greenhouse trials. At the early vegetative（three weeks after transplanting）, late vegetative（six weeks after transplanting） and flowering stages, plant height and number of tillers per plant were recorded. At the flowering stage, shoots were harvested and shoot dry weight, shoot P concentration, shoot P uptake and P utilization efficiency were measured. All data were statistically analyzed using analysis of variance, regression and cluster procedures. The measured parameters were significantly different between P₀ and P₃₀ conditions（P < 0.05）. Higher shoot dry weight was reported by the rice genotypes H4 and Marss under P₀ conditions. The regression analysis between shoot dry weight and P utilization efficiency revealed that the studied rice genotypes could be categorized to three P deficiency tolerance classes. A total of 13 genotypes could be considered as highly tolerant and 4 genotypes as sensitive for P deficiency. These results could be used to select parental genotypes for breeding and genetic studies and also to select interesting varieties or landraces for organic rice production.     

不同品种哺乳仔猪精氨酸代谢特性比较研究

我国地方品种猪与外来猪生长速度差异明显。鉴于精氨酸对仔猪生长发育的重要性,本研究选用14日龄哺乳的宁乡猪、湘西黑猪、蓝塘猪、巴马香猪、环江香猪和长白猪各12头,公、母各半,前腔静脉采血,离心分离血清,测定其中游离精氨酸和一氧化氮(NO)的浓度;采集肠道、肌肉、肝脏和肾脏等组织,测定其中的游离精氨酸浓度和NO合成酶(NOS)活性以及N-乙酰谷氨酸合成酶(NAGS,内源性精氨酸合成限速酶)mRNA的绝对表达量。结果表明,长白猪的血清精氨酸浓度显著高于(P<0.05)其他地方品种猪,血清NO浓度高于(P＞0.05)其他地方品种猪;各品种猪空肠前段和肝脏中的NOS活性最高,肾脏中的NOS活性最低;长白猪的空肠前段NOS活性仅低于宁乡猪,肝脏NOS活性仅高于环江香猪;在各个组织均检测到NAGS mRNA不同程度的表达,其中肠道和肝脏中的表达水平最高。综上所述,本研究揭示了不同品种哺乳仔猪血清精氨酸和NO浓度、3种主要组织游离精氨酸含量和NOS活性以及12种组织中NAGS基因的表达谱差异,为解释不同品种猪的生长表型差异提供了营养生化基础。     

Carotenoid composition and antioxidant activity of tortillas elaborated from pigmented maize landrace by traditional nixtamalization or lime cooking extrusion process

Mexican pigmented maize (Zea mays L.) landrace kernels have been scantily evaluated regarding potential as functional food. In this study, eight Mexican pigmented (yellow and red) maize accessions of Tuxpeño, Tabloncillo and Chapalote landraces collected in the northwestern region of Mexico were processed into tortilla to determinate carotenoid profiles, as well as their Oxygen Radical Absorbance Capacity for Lipophilic extract (ORAC-L). The total carotenoid content ranged from 3.66 to 5.56 mg LE/kg DW in the yellow maize and from 1.49 to 3.49 mg LE/kg DW in the red maize among all raw genotypes. Lutein and zeaxanthin were major carotenoids in all pigmented maize, accounting for ∼85% of total carotenoids. The traditional nixtamalization and lime-cooking extrusion process significantly (p < 0.05) decrease total carotenoid and ORAC-L assays when compared to raw kernels. Traditional tortillas retained among 72.0–87.6% and 65.1–78.8% of total carotenoids and ORAC-L levels respectively, compared to 68.8–79.5% and 60.3–75.5% assayed in extruded tortillas. Interestingly, traditional and extruded tortillas maintained more 72.7 and 60%, respectively; of the lutein concentration associated with raw grains. Our results suggest that yellow maize landrace could be considered for the elaboration of nixtamalized food products with nutraceutical potential.     

陕西省农家种大豆资源11S 和7S 球蛋白含量分析

利用SDS-PAGE分析了陕西省75份农家种大豆核心种质的11S和7S球蛋白亚基组成、相对百分含量和11S/7S比值,并对陕北、关中和陕南三个地区的资源材料进行了分析和比较。结果表明:大豆贮藏蛋白质由许多亚基组成,其中含量较高的有α′、α、β、A3、Acid和Basic;不同品种间大豆球蛋白组成几乎没有差异,但是各亚基的含量存在较大差异;75份供试材料的7S、11S球蛋白含量的平均值分别为36%和64%,变幅分别为28%~48%和52%~72%;11S/7S比值的变异幅度在1.09~2.53,平均值为1.78,高于2.0的种质有19个;陕北、关中、陕南三个地区农家种大豆群体11S/7S比值存在显著差异。     

中国不同省份籼稻地方品种的指纹图谱分析

【目的】通过对中国不同省份籼稻地方品种的SSR标记多样性分析,为中国籼稻地方品种的指纹图谱构建及其有效保护和利用提供理论依据。【方法】利用78对SSR引物,对中国14个省280份籼稻地方品种进行指纹图谱检测,分析不同省份籼稻地方品种间SSR标记遗传多样性差异、等位基因组成及其出现频率等。【结果】共检测到330个等位基因,每对引物等位基因数为2—12个,平均等位基因数为4.141个。RM336、RM334、RM264、RM297、RM204、RM248、RM444的等位基因数和有效等位基因数较多,分别在6和3以上,且遗传多样性指数较高,在1.4以上。78对SSR引物各等位基因的出现频率变异在0.18%—99.56%,RM338的A等位基因出现频率最高,RM131的E等位基因和RM276的F等位基因出现频率最低。RM338、RM308、RM484、RM29等44对SSR引物的某个等位基因在单个或多个省份籼稻地方品种中出现频率为100%。RM336、RM334、RM264、RM204、RM297、RM248、RM263、RM276、RM444、RM21、RM246和RM258等12对引物在多数省份中均表现为较高的遗传多样性。【结论】上述12对SSR引物适用于中国籼稻地方品种的指纹图谱构建。     

河南省玉米地方品种主要产量性状间的相关和通径分析

为了更有效的改良和利用现有的玉米地方品种,基于表型和基因型的聚类分析的基础上,从不同类群中筛选到46份河南省优异地方品种,进行产量及其相关性状的重复鉴定。相关和通径分析结果表明,对产量影响最大的是千粒重（r=0.7734）,其次为穗长和穗粗,均达极显著正相关,其中千粒重具有最大的正向直接通径系数（P=0.6518）,而穗行数对产量影响较小,未达显著水平。因此,提高千粒重,同时兼顾其它产量性状是提高河南地方品种产量的有效途径。结合田间株型等性状,从众多的地方品种中培育产量突出的自交系,为玉米育种积累材料,并为今后的相关研究提供参考。     

新疆小麦地方品种遗传多样性的SSR分析

为了评价新疆小麦地方品种的遗传多样性,利用42对SSR引物对75份新疆小麦地方品种进行遗传多样性分析。结果表明：在75份地方品种中42个SSR位点共检测到317个等位变异,等位变异变化范围为2~15个,平均7.55个;多态性信息指数(PIC值)变化范围为0.169~0.905,平均0.696。基因组的平均等位变异是D＞B＞A,遗传多样性指数为B＞D＞A。聚类分析表明75份供试新疆小麦材料可划分为3大类8亚类,聚类结果与材料的生态型密切相关,冬小麦地方品种和春小麦地方品种分别归属不同的类或亚类,春小麦地方品种的遗传多样性高于冬小麦地方品种,同时也反映了一定的地域特性。总之,新疆小麦地方品种具有丰富的遗传多样性,可用以拓宽育成品种的遗传基础。     

贵州地方水稻品种的SSR遗传多样性分析

利用21对SSR引物对74份贵州"禾"水稻品种及6份国际上常用的典型籼稻和粳稻品种进行遗传多样性研究。共检测到92个等位基因,每个位点的等位基因数变幅为2~9个,平均4.381个;平均Shannon信息指数为0.935,变幅为0·2793~1.8732;期望杂合度为0.5145,范围在0.0988~0.8313;品种间遗传相似系数为0.64~0.98。UPGMA聚类分析表明,在相似系数为0.682处可将"禾"品种分为4大类,大部分材料被聚类到典型粳稻的附近,品种间的亲缘关系与地理来源关系不大;主坐标分析结果与UPGMA聚类结果基本吻合。SSR检测结果表明,贵州省水稻地方品种——"禾"的多样性程度较低,且大多数属于粳稻。     

太湖流域粳稻地方品种产量相关性状的遗传分析

采用主基因+多基因混合遗传模型,对亲本穗部性状差异较大的3个杂交组合,大头稻/呆长青（组合Ⅰ）、老来红/盐粳2号（组合Ⅱ）和呆长青/上海青（组合Ⅲ）的后裔世代的产量相关性状进行了遗传分离分析,得到了这些性状的最适遗传模型。结果表明：组合Ⅰ每穗总粒数的最适遗传模型为一对主基因+加性 显性多基因混合模型,而组合Ⅱ、Ⅲ为一对完全显性主基因+加性 显性多基因遗传模型;组合Ⅱ、Ⅲ的单株有效穗数受一对主基因控制,组合Ⅰ则受两对主基因控制;组合Ⅰ、Ⅱ千粒重的遗传模型为两对主基因+多基因模型,组合Ⅲ为一对主基因+多基因遗传模型;每穗实粒数为两对主基因遗传模型。选用P1、P2、F1、B1、B2、F2六世代联合分离分析方法,相比于单个分离世代的分析方法,增加了试验的精确度,保证了分析结果的准确性,并可鉴别多基因的存在。根据试验结果,分析了不同性状、不同组合的育种策略。     

The traditional inexplicable replacement of seed and seed ware of landraces and cultivars: A review

A review is presented on the often inexplicable seed replacement by farmers. Such a seed replacement has been mentioned since Biblical times and earlier. It occurred and still occurs all over the world and for all cultivated plants. In order to find out whether or not this seed replacement has some meaningful background, farmers in those areas where this type of seed replacement still takes place should be interviewed. Maybe, this seed replacement is based on farmers' experience since times immemorial in which farmers obtained (or believed to obtain) lower yields if seed is not replaced. If so, the cause of this type of seed replacement can be explained. This revised version was published online in August 2006 with corrections to the Cover Date.