Production and use of maize seed for sowing in Bolívar,Ecuador     

Frank P. Duijndam  Christiaan J. Evenhuis  Jan E. Parlevliet 《Euphytica》2007,153(3):343-351

In the province of Bolívar in the Andean region 212 farmers, six salesmen and 14 technicians, involved in maize production, were interviewed. The majority of the farmers interviewed were small-holders; 64% of the farmers had a farm size of less than 4.5 ha. Maize is the most important crop and is often grown in association with beans. Most maize, 96%, is soft maize meant for human consumption. The cultivars grown are open pollinated ones. One cultivar, ‘Guagal’, was grown extensively. A few others, among which an improved version of Guagal were of some importance. In the production of maize the farmers consider damage due to insects, wind (lodging), diseases, drought and hail, the low prices for their surplus maize and the high costs of fertilizers, chemicals, sowing seed and labour as the most important constraints. The seed for sowing the next crop mainly came from seed kept from the last harvest. Farmers indicated that they select from the harvested ears the healthy looking larger ones. Kernel type also was a selection criterion. Selection for plant type in the field was rarely done. Of the farmers 71% stored the maize as kernels while 29% stored the seed kept on the ears. The storage was predominantly done somewhere in the house in plastic (56%) or cloth bags (14%), in a pile (13%), just on the floor (4%) or in cans (4%). Some farmers still had seed left from the last sowing and were willing to give a sample for testing. From 32 such samples the quality was assessed by INIAP, the Ecuadorean governmental research and breeding organisation. The samples were consistently of a low quality. Especially the vigour of the seedlings was poor and most of the seeds were infected or contaminated by fungi. In the region a few salesmen offer maize seed for sale of cultivar Guagal at prices affordable by the farmer. Of improved cultivars the prices were higher than most farmers are willing to pay. The technicians considered good seed quality and good maintenance of the cultivars effective methods in obtaining better yields. Many farmers do not have access to seed of INIAP and are not familiar with the improved cultivars.  相似文献   

研究和发展益生菌和益生元的前瞻     

高山峨  张志强 《农产品加工．学刊》2006,(8):85-87,89

人体的结肠微生物区对健康有着极大的影响。自从引入益生菌和益生元的概念后,对人体肠微生物区组成的观点产生了极大的变化,详细研究复杂的细菌群落一直是个巨大的挑战。用抽样法研究肠微生物群将会更加成熟,并广泛应用于此项研究中。目前,以核酸为基础的分析方法是研究肠微生物区系的基本工具。应用先进的分子技术,使点查和鉴定结肠细菌的种类以及族系级别成为可能。目前正在对第二代益生元的概念展开广泛研究。了解内脏生态系统的作用机制以及处于内脏生态系统中的细菌的作用机制,对于益生菌和益生元将来的发展极为重要。  相似文献   

春播早熟区玉米杂交种稳产性的研究   总被引：1，自引：0，他引：1  

苏书文  高合明  郭新林 《华北农学报》1986,(3)

在同一年份区试中,玉米杂种间两种稳产性参数有相当大的差异;在不同年份区试中,有的杂交种两种稳产性参数无明显差异,有的则差异很大,说明这些杂交种在不同年份、气候和环境条件下有不同的稳产性和适应性.杂交种通过连续三年区试之后,才能更好的评价其稳产性.杂交种的平均产量与其稳产性参数间的相关系数不显著(r(?)=0.0612,r(?)=-0.2933).杂交种稳产性与主要农艺性状特别是果穗性状变化相关联.在作物品种区域化试验中,这一分析方法似乎是育种工作者研究品种产量稳定性和适应性的一个有效工具.  相似文献   

氮磷钾肥施用量对稻米直链淀粉含量和淀粉粘滞特性的影响     

徐大勇  金军  胡曙鋆  王学红  高云  朱庆森 《中国农学通报》2004,20(5):99-99

通过盆栽和大田试验,研究了N、P、K肥对稻米直链淀粉含量和淀粉粘滞特性的影响。结果表明,N肥施用量增加,直链淀粉含量、最高粘度和崩解值下降,消碱值和回复值上升。增施P肥对直链淀粉含量影响不明显,对最高粘度、崩解值、消碱值和回复值影响效用,供试品种间变化趋势存在差异。K肥施用量增加,各品种均表现出直链淀粉含量、最高粘度、崩解值上升趋势,消碱值和回复值呈下降趋势。对NPK肥,不同品种反应程度不同,品种与N、P、K之间,N、P、K三者之间都存在互作效用。减少N肥用量,适量增施K肥有利于稻米食味品质的提高。  相似文献   

Effects of inbreeding on nodal root system morphology and architecture of white clover (<Emphasis Type="Italic">Trifolium repens</Emphasis> L.)     

Shirley N. Nichols  James R. Crush  Derek R. Woodfield 《Euphytica》2007,156(3):365-373

Plants of white clover (Trifolium repens L.) cultivar Crau, a self-fertile Crau genotype, and nine generations of inbred progeny were raised in sand culture in a glasshouse experiment. Digital images of the root systems were made and root morphological characteristics were determined on all the plants. Root architectural parameters were measured on the Crau parent and the S₁, S₄, S₆, and S₉ inbred lines. The clover roots became shorter and thicker with inbreeding but the number of root tips per plant was unchanged. Root architecture (branching pattern) was largely unaffected by inbreeding. It is concluded that inbreeding white clover will lead to shorter, thicker roots, and reduced nutrient uptake efficiency compared with the parent clover. The degree to which these deleterious traits are overcome during the development of F₁ hybrids needs to be determined.  相似文献   

Quantitative trait loci for phytate in rice grain and their relationship with grain micronutrient content   总被引：6，自引：0，他引：6  

James C. R. Stangoulis  Bao-Lam Huynh  Ross M. Welch  Eun-Young Choi  Robin D. Graham 《Euphytica》2007,154(3):289-294

Phytate (inositol-hexa-phosphate) has an important role in plants but it also may have anti-nutritional properties in animals and humans. While there is debate within the plant breeding and nutrition communities regarding an optimum level in grain, there appears to be little information at the molecular level for the genetics of this trait, and its association with important trace elements, in particular, Fe and Zn. In this preliminary study, quantitative trait loci (QTL) for grain phytates, Zn and Fe in glasshouse-grown rice lines from an IR64 × Azucena doubled haploid population were identified. Correlations between phytate and essential nutrients were also studied. Transgressive segregation was found for most traits. Phytate and total P concentrations had one QTL in common located on chromosome five with the (high concentration) allele contributed from Azucena. There were significant positive correlations between phytate and inorganic phosphorus (P), total P, Fe, Zn, Cu and Mn concentrations for both grain concentration and content. However, the QTLs of phytate were not located on the same chromosomal regions as those found for Fe, Zn and Mn, suggesting that they were genetically different and thus using molecular markers in breeding and selection would modify the phytate level without affecting grain micronutrient density.  相似文献   

新疆棉花高体细胞胚胎发生能力基因型的筛选   总被引：4，自引：0，他引：4  

周小凤  张碧瑶  刘冠泽  高巍  余渝  邓福军  李保成  孔宪辉  张献龙  金双侠 《分子植物育种》2007,5(6):819-826

本研究以15个新疆主栽优良品种(系)以及两个对照品种YZ-1和Y668为研究对象,利用下胚轴做外植体进行胚胎发生能力的比较研究,筛选出了5个能够胚胎发生的基因型,即新陆早12,新陆早17,新陆早22,新陆早32和新陆早33,其中新陆早32和新陆早33,能在3个月左右分化,且分化率较高,可达90%左右,其它3个品种的分化效率为:新陆早17为46.9%,新陆早12为35.1%,新陆早22为25.3%,但这3个品种的分化时间都比较长,需5个月左右.同时对5个再生品种及两个对照品种的成胚效率进行了比较,由新陆早32和新陆早33诱导的胚性愈伤在胚状体数目及胚胎萌发效率都比较高,具备作为棉花优良遗传转化受体的基本特征,目前已经用于农杆菌介导的转基因试验.上述研究拓展了棉花组织培养及转基因的受体范围,为新疆棉区转基因育种研究工作的开展提供了重要基础材料.  相似文献   

Monosomic addition lines of Beta corolliflora in sugar beet: plant morphology and leaf spot resistance   总被引：2，自引：0，他引：2  

D. Gao  C. Jung 《Plant Breeding》2002,121(1):81-86

Monosomic addition lines in Beta vulgaris from Beta corolliflora were described morphologically and characterized for disease resistance. Monosomic addition plants (2n= 19) were selected among segregating offspring by a squash dot technique in combination with B. corolliflora‐specific probes. Plants carrying an added chromosome were characterized by leaf shape, plant size and plant vigour. In this way, most addition lines could be distinguished from diploid beets, however, to identify those plants unequivocally, molecular marker analysis was also necessary. Transmission frequencies of each addition line were determined to be in the range 13.9% (Cor‐4) to 60% (Cor‐9). High transmission rate of addition line Cor‐9 was assumed to be due to apomictic propagation because transmission rate after selfing cannot exceed 50%. Cercospora leaf spot resistance tests were performed on 167 monosomic plants from seven different addition lines, two fragment addition lines and 89 diploid controls. No line exhibited complete resistance, but the monosomic additions Cor‐3 and Cor‐4 showed significantly lower infection rates than their diploid sibling plants. The identification of monosomic addition lines with apomictic and disease resistance characters offers the possibility of transferring those genes to sugar beet.  相似文献   

特优559产量构成因素及丰产稳产性分析   总被引：2，自引：0，他引：2  

孙明法  姚立生  高恒广  顾来顺  何顺椹  严国红  唐红生 《种子》1997,(4)

应用数理统计方法对特优559产量构成因(?)及丰产稳产性进行了分析,结果表明:特优559丰产性、稳产性好,适应性强。产量构成因素中以穗数与产量的关系最为密切,对产量的作用最大,其次是每穗总粒数,再次是结实率,千粒重对产量的作用不大。揭示其高产途径和主攻目标是“攻足穗,争大穗,提高结实率,稳定粒重”,使穗、粒、重协调发展,夺取高产。  相似文献   

Wheat grain yield and stability assessed through regional trials in the Eastern Gangetic Plains of South Asia     

Ram C. Sharma  G. Ortiz-Ferrara  J. Crossa  M. R. Bhatta  M. A. Sufian  J. Shoran  A. K. Joshi  R. Chand  Gyanendra Singh  R. Ortiz 《Euphytica》2007,157(3):457-464

Improving the level and stability of grain yield is the primary objective of wheat breeding programs in the Eastern Gangetic Plains (EGP) of South Asia. A regional wheat trial, the Eastern Gangetic Plains Yield Trial (EGPYT), was initiated by CIMMYT in collaboration with national wheat research programs in Bangladesh, Nepal, and India in 1999–2000 to identify wheat genotypes with high and stable grain yield, disease resistance, and superior agronomic traits for the EGP region. A set of 21 wheat experimental genotypes selected from a regional wheat screening nursery in South Asia, three improved widely grown cultivars (Kanchan, PBW343 and Bhrikuti), and one long-term cultivar (Sonalika) were tested at 9–11 sites in six wheat growing seasons (2000–2005) in the EGP. The 21 experimental genotypes were different in each year, whereas the four check cultivars were common. In each year, one or more of the experimental genotypes showed high and stable grain yield and acceptable maturity, plant height, and disease resistance compared to the check cultivars. Three improved cultivars have already been commercially released in the region through EGPYT and many germplasm lines have been used in the breeding programs as parents. Identification of wheat genotypes with high-grain yield in individual sites and high and stable yield across the EGP region underlines their value for regional wheat breeding programs attempting to improve grain yield and agronomic performance.  相似文献