糜子分子遗传研究进展与展望

糜子是最古老的驯化栽培作物之一,具有抗旱、耐瘠、水分利用效率高、营养丰富等特点,在北方旱作农业区特色粮食生产中占有重要地位。为深入推动糜子农艺、产量及品质相关性状遗传解析,在介绍国内糜子遗传研究现状基础上,通过文献分析综述了糜子分子遗传研究进展,并展望了未来发展趋势。     

Collection and morphological characterization of Panicum coloratum L. in Argentina

Panicum coloratum (Poaceae) is a perennial grass native to South Africa, distributed all over the world, but poorly adopted by ranchers in Argentina. Adapted to a wide range of soil and climatic conditions, it constitutes a good forage resource for zones with edaphic and climatic restrictions, where cattle rising activities are here displaced. The high polymorphism in the species has made it difficult to delineate sub specific taxonomic categories. It has been classified in botanical varieties, types and/or cultivars. In order to document the morphological variability in P. coloratum and to investigate the differences between var. makarikariense and var. coloratum, a collection was gathered in INTA Rafaela composed by fourteen accessions from different provinces of Argentina: six accessions of var. makarikariense and eight from var. coloratum. The evaluation of 152 individuals gives evidence of a wide morphological variation in the collection in traits related to forage and caryopses production; seven out of nine traits showed significant differences between var. makarikariense and var. coloratum. Based on the study of local type specimens, a morphological key to distinguish between P. coloratum varieties is provided. These results report new information about the diversity in P. coloratum in Argentina and provide valuable insights for future use of the collection as the base material of a breeding program.     

Chemical and Physical Characteristics of Proso Millet (Panicum miliaceum)‐Based Products

Celiac disease and gluten sensitivities, as well as obesity and overweight‐related disorders, have led to the investigation of gluten‐free grains and development of new food products. To address this, refined proso millet and refined corn (control), both gluten‐free grains, were used to produce four different product types (muffin, couscous, extruded snack, and porridge). The products contained four different grain combinations (100% proso millet, 75% proso millet/25% corn, 25% proso millet/75% corn, and 100% corn). All products were evaluated for their nutritional composition, in vitro starch digestibility, and expected glycemic index (eGI). Products made with refined proso millet had increased protein (7.6–11.3%), lipid (1.2–6.1%), fiber (7.0–8.8%), and phenolic content (323.5–425 μg/g) compared with those incorporating corn flour (2.5–9.0%, 0.8–4.0%, 2.1–4.1%, and 213–315 μg/g, respectively). As the proso millet content increased, the eGI decreased significantly (P < 0.05). Products made from refined proso millet appear to be good candidates for producing low‐GI, gluten‐free foods.     

Isolation and Analysis of Genes Induced by Rehydration after SeriousDrought in Broomcorn Millet (Panicum miliaceum) by Using SSH

利用抑制消减杂交(suppression subtraction hybridization，SSH)技术构建了糜子(Panicum miliaceum)干旱后复水条件与正常浇水条件下基因差异表达的SSH-cDNA文库。对其中的60个阳性克隆进行了测序，在去除冗余的cDNA后，利用NCBI的BLAST软件在GenBank 中进行核酸和蛋白质同源性的比较和功能分析。核酸比对结果表明,有32个cDNA片段与已知cDNA片段具有较高的同源性，且多数与植物受到生物或非生物胁迫时的反应机制相关，同时有11条序列与小鼠肝被手术切除后再生时产生的EST有一定同源性。蛋白分析结果显示，有28个序列与已知功能蛋白序列同源性较高，这些功能蛋白涉及植物体内的信号转导、转录调控及蛋白加工等。实验结果表明糜子在干旱复水条件下可诱导一系列特异基因的表达。     

Origin and domestication of Lactuca sativa L.

The domestication of lettuce, Lactuca sativa L. is described on the basis of literature study. The centre of origin is discussed. A historical survey is made of the distribution of the groups of Lactuca cultivars over the world.     

Geographic distribution of Waxy gene SNPs and indels in foxtail millet, Setaria italica (L.) P. Beauv.

To elucidate diversity and evolution of the Waxy gene in foxtail millet, Setaria italica, we analyzed sequence polymorphism of Waxy gene in 83 foxtail millet landraces collected from various regions covering the entire geographical distribution of this millet in Europe and Asia. We found a unique geographic distribution pattern at the sequence level of gene haplotypes and also found a large diversity in East Asian landraces. We also found a higher degree of genetic polymorphism in a non-waxy phenotype than in other low amylose types, supporting the hypothesis that low amylose types recently originated from non-waxy type.     

不同立地柳枝稷生长响应的初步研究

对黄土丘陵区不同立地中柳枝稷生长响应的变化规律进行了研究。结果表明:柳枝稷在不同立地条件下土壤水分明显不同,坡地土壤平均含水量(13.39%)<梯田(14.78%)<川地(16.02%)。土壤水分含量,根系生物量和土层深度三者存在密切相关性。在梯田、坡地和川地三种立地条件下,柳枝稷的株高、覆盖度、生物量、杂草和枯落物等均存在明显差异,其中柳枝稷的株高和覆盖度表现为川地>坡地>梯田;伴生杂草和柳枝稷枯落物与地上部生物量表现一致,川地显著高于坡地和梯田。地下生物量在川地、坡地和梯田立地下均呈现相同规律,随深度变化根系量逐渐减少,三种立地条件下总地下生物量差异不明显。同时发现土壤有机质和N含量与柳枝稷生产力呈显著正相关,说明了黄土丘陵区柳枝稷的生长响应与立地水肥条件有关。这对加强优良禾本科牧草的生态适应性研究及促进我国黄土高原生态可持续发展以及退耕还草工程具有重要的现实意义。     

Geographical variation of nuclear genome RFLPs and genetic differentiation in foxtail millet, Setaria italica (L.) P. Beauv.

Sixteen RFLP loci in 62 landraces were assayed to study geneticdifferentiation in foxtail millet, Setariaitalica (L.) P. Beauv. Among 52 bands, 47 werepolymorphic among foxtail millet landraces. A dendrogram constructedbased on RFLPs was divided into five major clusters (clusterI–V). Clusters I and II contained strains mainly from EastAsia. Cluster III consisted of strains from subtropical and tropicalregions in Asia such as Nansei Islands of Japan, Taiwan and thePhilippines and India and cluster IV consisted of some strains fromEast Asia, a strain from Nepal and a strain from Myanmar. Cluster Vcontained strains from central and western regions of Eurasia such asAfghanstan, Central Asia and Europe. Chinese landraces wereclassified into four clusters. These results indicate that foxtailmillet landraces have differentiated genetically between differentregions and that Chinese landraces were highly variable.     

Origin and nature of halloysite in Ando soils from Towada tephra,Japan

The origin and nature of halloysite in Ando soils from Towada tephra were investigated. These soils were formed from five tephras: Towada-a (1,000 years old), Towada-b (2,000 years old), Chuseri (4,000 years old), Nanbu (8,600 years old) and Ninokura (10,000 years old).Formation of halloysite took place only in the buried soils from Nanbu and Ninokura tephras occurring in an “accumulating zone”, where thicknesses of overburden tephra deposits were mostly 2.5 m or greater and silica enrichment of the clay fractions could occur.The amounts of halloysite were greater in (1) the soils from Ninokura tephra than in those from Nanbu tephra, and greater in (2) the humus horizons as compared to the nonhumus horizons of these same soils. The mean sizes of spheroidal halloysite particles and the ratios of numbers of tubular to spheroidal forms differed with differences in soil horizons and age.High-resolution electron micrographs of glycerol-solvated spheroidal halloysite particles had lattice images of 11 Å due to (001) from the exterior to the interior and had no indications of layer separation. Moreover, the central core of spheroidal halloysite with a diameter of 150 Å showed neither layer structure nor allophane spherules.Results obtained in this study thus indicate that spheroidal and tubular forms of halloysite were formed concurrently in these Ando soils.     

Application of random amplified polymorphic DNA to study genetic diversity in Paspalum scrobiculatum L. (Kodo millet, Poaceae)

Summary Genetic diversity and patterns of geographic variation among collections of Paspalum scrobiculatum (kodo millet) and P. polystachyum were studied using molecular markers generated through the random amplified polymorphic DNA (RAPD) method. A high level of polymorphism in RAPD markers was observed among the individual accessions, demonstrating the high genetic diversity of the crop. The markers obtained from the RAPD method were analyzed with the cluster analysis, principal coordinates and minimum spanning tree methods. Three major groups were resolved, one representing the African accessions, and two for the Indian accessions. The accessions of the north African kodo millet and P. polystachyum (considered conspecific with P. scrobiculatum) were quite distinct. The Australian kodo millet showed higher affinity to the African types. The study demonstrated that the RAPD technique can be applied to resolving degrees and patterns of genetic variation at the population and species levels, identifying cultivars, and defining gene pools of this crop.     

Insect resistance of a full sib family of tetraploid switchgrass Panicum virgatum L. with varying lignin levels

Little information is available on insect resistance mechanisms and inheritance in biomass grasses. Although reduction of lignin in biomass grasses in order to increase the efficiency of fermentation may result in increased susceptibility to insect feeding, other resistance mechanisms may be more important. Field grown leaves of two tetraploid parent (Kanlow N1, Summer) and 14 progeny switchgrass (Panicum virgatum L.) plant clones selected for a diversity of plant form and ranges in lignin levels were tested for leaf resistance to feeding by the fall armyworm (Spodoptera frugiperda J. E. Smith), a grass feeding insect pest. Although lignin generally appeared important as a resistance mechanism only at early season stages, replicate clones of two low lignin progeny plants generally remained resistant to fall armyworm feeding. Mechanical damaging increased resistance to fall armyworm feeding in several of these plants. Degrees of resistance were sometimes associated with leaf form of progeny. These results indicate there are likely multiple insect resistance mechanisms operating at different stages in switchgrass, and that segregation of some mechanisms appears related to growth form of the plants.     

Genetic diversity and structure of natural and agronomic switchgrass (Panicum virgatum L.) populations

Panicum virgatum L. (switchgrass) is an obligate outcrossing C₄ perennial prairie grass currently being pursued for the production of lignocellulosic ethanol. Commercial production of switchgrass for bioenergy has increased substantially in the United States. Understanding the degree of native genetic diversity within and among switchgrass populations will facilitate effective germplasm improvement, conservation, and management programs. In this study, the genetic diversity and differentiation among natural and agronomic switchgrass populations were analyzed at the molecular level by using random amplified polymorphic (RAPD) DNA markers. The mean genetic diversity among populations ranged from 0.051 ± 0.136 to 0.243 ± 0.214 and the mean genetic similarity among all the switchgrass populations was 0.775. The clustering pattern of switchgrass populations grouped the individuals based on their sites of origin, with agronomic cultivars predominantly separated into distinct clusters. The grouping of individuals within and across the populations was corroborated by principal component analysis. These results are consistent with previous reports for switchgrass accessions. RAPD DNA markers were suitable for quickly estimating the genetic diversity of native and agronomic switchgrass populations, and suggest that introgression of agronomic genes into natural switchgrass populations and subsequent changes in genetic structure may be detectable.     

Microsatellite variability within and among local landrace populations of tea, Camellia sinensis (L.) O. Kuntze, in Kyoto, Japan

Genetic variability within and among eight landrace populations of tea (Camellia sinensis (L.) O. Kuntze) located in southern Kyoto, Japan, was surveyed with six microsatellite markers. The average number of alleles per locus was 3.83 to 4.67 for landrace populations, whereas the corresponding value among modern cultivars and breeding lines was 6.63. Expected heterozygosity values averaged over loci within landrace populations ranged from 0.498 to 0.723. A similar level of variation, 0.682, was observed for cultivars and breeding lines. High fixation index values (0.177–0.417) for each population are consistent with biparental inbreeding within the population. Genetic differentiation among local populations was extremely low with F _ST = 0.062, although AMOVA revealed significant differentiation among landrace populations. We propose that these populations share a common ancestral gene pool and that some degree of artificial selection within each population has been performed by local farmers. Neighbor-joining analysis revealed that genetic relationships among populations reflect geographical location of populations. This might result from more frequent genetic exchange by nearby farmers.     

基于遗传算法的基质培黄瓜营养液配方优化（英文）

为探究施肥多因子耦合对黄瓜产量、品质、肥料利用率等方面的综合调控,获取适宜的基质栽培营养液配方。以'博耐526'黄瓜为试材,通过四因素（N、K、Ca、Mg）五水平（1/2）二次正交旋转组合设计,共23个处理,利用四元二次回归分析建立了N、K、Ca、Mg对黄瓜产量品质综合评分的回归模型,分析了双因素与三因素耦合效应对黄瓜产量品质综合评分的影响。结果表明,各因素对黄瓜产量品质综合评分的影响程度由大到小依次为氮、钾、钙、镁,黄瓜产量品质综合评分随各因素的增加均呈现先增加后减小的趋势。N-K和N-Ca的耦合效应显著（P<0.05）,而其余因素耦合效应不显著（P>0.05）;N-K耦合效应对黄瓜产量和品质综合得分的影响为负,而N-Ca耦合效应为正。同时建立了黄瓜产量品质综合评分、氮、钾和钙利用率的多目标优化模型,利用遗传算法对该模型进行模拟寻优,得到优化的氮,钾,钙和镁浓度分别为14.83、6.89、3.55和4.17 mmol/L。在此条件下,黄瓜的单株产量、可溶性蛋白、维生素C和可溶性总糖含量分别比山崎黄瓜专用配方处理显着提高了21.07%,40.91%,53.33%和11.48%,有机酸和硝酸盐含量比山崎黄瓜专用配方处理显著降低,此结果可为基质栽培黄瓜高产优质和营养液科学管理提供指导依据。     

基于遗传算法的基质培黄瓜营养液配方优化

为探究施肥多因子耦合对黄瓜产量、品质、肥料利用率等方面的综合调控,获取适宜的基质栽培营养液配方.以'博耐526'黄瓜为试材,通过四因素(N、K、Ca、Mg)五水平(1/2)二次正交旋转组合设计,共23个处理,利用四元二次回归分析建立了N、K、Ca、Mg对黄瓜产量品质综合评分的回归模型,分析了双因素与三因素耦合效应对黄瓜...