Controlled pollination transfer of a nuclear male-sterile gene from a diploid to a tetraploid watermelon line

Summary A recessive male-sterility (ms) gene was transferred from a diploid to a tetraploid watermelon (Citrullus lanatus (Thunb.) Matsum and Nakai) line through a series of controlled pollinations. Progeny testing and morphological characteristics confirmed the development of tetraploid lines containing the ms gene. The possible use of this gene transfer system in the improvement of tetraploid watermelon cultivars and the use of male-sterile tetraploids in the production of seedless triploid watermelons is discussed.     

民企老板十年民告官的"精神胜诉"--访河南省某县种子广场总经理张书智

在河南省某县种子广场,张书智在自家种子门市部里办起了"普法超市".房间里两架一人多高的书柜中,摆满了有关法律书报杂志,有 3000多册书、 1O00多份杂志.凡是到这里的农民均可享受免费法律咨询、协助起草法律文书、借阅书报杂志等服务."普法超市"开办两个多月,接待了来自四面八方的"顾客" 800余人次,收到全国各地的咨询信函 500多封,他们所遇到法律方面的困惑和难题均得到满意的解答.     

Prediction of the Line Value of a Genotype from a Top Cross with a Single Cross Hybrid

With the assumption of biallelism it is shown that differences in line values of genotypes from a random mating population can be predicted by the differences of values in top cross progenies with a heterozygous tester. This prediction is also valid in the case of multiallelism with a constant degree of dominance for each pair of alleles and if the tester is heterozygous for the more “distant” alleles. With an arbitrary tester, the efficiency of the prediction is affected by the proportion of the loci which are heterozygous for the more distant alleles. However, with the assumptions considered on multiallelism, with partial to complete dominance, the correlation between line value and combining ability with the tester is expected to be high for a large range of the repartition ot the loci. A two tester top cross design using highly complementary lines, could also be used.     

Solanum scabrum—a potential source of a coloring plant extract

The objective of this study was to examine the potential of Solanum scabrum to provide a colorant for food. We conducted a field trial with eight accessions from four different sources and recorded both morphological variability and fruit yield differences between accessions. Further, anthocyanin and glucoalkaloid concentrations were determined. The accessions could be assigned to two distinct groups: a leafy vegetable type with toxic fruits used in Africa and a berry type with edible fruits known as Garden Huckleberry in North America, but both types had edible leaves with low glucoalkaloid concentrations. The leafy vegetable type set not much fruit. In contrast, the berry type yielded on average 800–900 g berries per plant with remarkable high anthocyanin concentrations of 8.1–13.9 g kg⁻¹ fresh weight, calculated as petunidin 3-p-(coumaryl-runtinoside)-5-glucoside. Thus, S. scabrum can serve as a source for natural anthocyanin pigments. In particular, two accessions with a high fruit yield were promising candidates as a berry crop. One had the best anthocyanin concentration of the examined material and the other one had a low percentage of unripe berries as a further advantage.     

Radon anomaly as a possible precursor of a submarine earthquake

In the framework of investigating the ventilation of deep-sea basins in the Indonesian archipelago, ²²²Rn was determined in near bottom water samples. In one of these basins, the Halmahera Basin, excess ²²²Rn concentration and the related standing crop was unexpectedly high. At this station excess Radon has an almost uniform concentration of about 2 dpm·kg⁻¹ up to 120 meters above the bottom. In this paper the possibility is discussed that the high standing crop in this basin is connected with three submarine earthquakes with a magnitude of resp. 4.4, 5.4 and 5.9 mb that took place four days after we took the samples, possibly in combination with submarine faults, which are typical for the Indonesian archipelago. The epicentres were within 100 km from the station. All over the world variations in ²²²Rn concentrations have been observed prior to earthquakes (up to 500 km from the epicentre). This can be regarded as an important non-seismic precursor to earthquakes, but it has to our knowledge never been observed in deep-sea basins.     

A mutant of a mutant of a mutant of a...: Irradiation of progressive radiation-induced mutants in a mutation-breeding programme with Chrysanthemum morifolium Ram.

Summary Radiation-induced sports in Chrysanthemum morifolium Ram. have been reported for several years. It has become an everyday practice to produce flower-colour mutants from outstanding cross-breeding products, even before they are distributed for the commercial production of cut flowers.One of the most successful and recent examples is that of cv. Horim, of which hundreds of mutants were produced by successive use of radiation-induced mutants in the mutation-breeding programme. Over about 4 years a variety of flower-colour mutants was obtained, not only largely including the outstanding characteristics of the original cultivar but sometimes even with an appreciable improvement in quality and yield. It is expected that the latter types, the Miros group, will soon completely supersede the spontaneous or radiation-induced Horim sports and mutants and take over the leading position of the Horim group in the production of all-year-round (AYR) cut flowers.     

Quantitative trait loci for grain yield and yield components in a cross between a six-rowed and a two-rowed barley

Summary The positions of quantitative trait loci (QTL) for yield and yield components were estimated using a 85-point linkage map and phenotype data from a F₁-derived doubled haploid (DH) population of barley. Yield and its components were recorded in two growing seasons. Highly significant QTL effects were found for all traits at several sites in the genome. A major portion of the QTL was found on chromosome 2. The effect of the alleles in locus v on thousand grain weight and kernels per ear explained 70–80% of the genetic variation in the traits. QTL × year interaction was found for grain yield. Several different QTL were found within the two-rowed DH lines compared to those found in the six-rowed DH lines. Epistasis between locus v and several loci for yield and yield components indicates that genes are expressed differently in the two ear types. This may explain the difficulties of selecting high yielding lines from crosses between two-rowed and six-rowed barley.Abbreviations DH doubled haploid - QTL quantitative trait locus/loci - RAPD random amplified polymorphic DNA - RFLP restriction fragment length polymorphism - T. Prentice Tystofte Prentice - V. Gold Vogelsanger Gold     

Immobilization of heavy metals in a polluted soil of a sewage farm by application of a modified aluminosilicate: a laboratory and numerical displacement study

The efficiency of the modified alumino-silicate “Berengite” to fix heavy metals in contaminated soils was studied using a soil from a former sewage disposal site with high loads of Zn and Cd. The immobilization effects for different additions of Berengite were described on the laboratory scale with the cation exchange capacity and a two component Freundlich sorption isotherm. Long term displacement of Cd and Zn were calculated with a numerical simulation model. The simulation studies show a rather high immobilization of Zn and Cd in the solid phase for the next 80 years. Far more Berengite is required for the fixation of Cd than for Zn.     

Analysis of a backcross population from a multi-copy transgenic Brassica napus line

Brassica napus is one of the crops at the forefront of biotechnological development. The procedures used to produce transgenic varieties are all prone to generating plants with multiple transgene copies. There has been considereable interest in the behaviour of such multi-copy lines because gene dosage rarely appears to correlate simply with gene expression. Here we report the analysis of a population of 107 progeny from a B. napus transformant containing multiple copies of a GUS marker gene construct. A total of 12 GUS sequence copies were identified including one that was non-functional. The expression of GUS increased with increasing copy number but this increase only made up a small proportion of the total variation between lines. There was no evidence of interaction between the various GUS copies and they appeared to segregate independently. The variation between progeny lines indicated that the number of gene copies was not a good guide to the expression of the gene product and hence that the expression of the gene in progeny from a multiple-copy parent could not be predicted. The importance of these findings in relation to plant breeding and the risk assessment process is discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Optimization of a web based query system for a magnesium alloy database

Based on an existing magnesium alloy database, a query system is optimized by considering the design characteristics, and an integrated query system for this magnesium alloy database is developed to meet the demands of more users. The result shows that the new system improves the query efficiency of the magnesium alloy database, especially for queries concerning phase diagrams and the structure of magnesium alloys. This means that the new system provides users a more powerful and useful magnesium alloy database.     

Unique meiotic behaviourin F1 plants from a cross between a non-tuberous and a tuberous Solanum species in section Petota

Uniformly abnormal meiotic behaviour was observed in 12 F₁-plants from a cross between Solanum etuberosum (non-tuberous) and S. pinnatisectum (tuberous). Per pollen mother cell at MI an average was found of 3.64 bivalents (all rodshaped, 1–2 per cell, heteromorphic), 16.64 univalents (scattered haphazardly on a continuous bipolar spindle) and 0.03 trivalents (all Y-shaped). Lagging chromosomes and precocious division of univalents very frequently occurs, leading to unequal distribution of chromosomes, aneuploid gametes and male sterility. Heteromorphic bivalents at MI, loops in bivalents at pachytene and non-disjunction in one hybrid plant, point to a highly abnormal meiotic behaviour. The occurrence of few trivalents is discussed.Considering that according to the literature nearly normal pairing was observed in the intergeneric F₁-hybrids Lycopersicon esculentum × Solanum lycopersicoides and L. esculentum x S. pennellii, the lack of chromosome pairing in an interspecific F₁-hybrid, of which both Solanum parents belong to the same section, is paradoxical to a plant breeder and might even be conspicuous to a taxonomist.     

Economic Impact of a Port on a Regional Economy: Note

ABSTRACT This paper attempts to identify and adjust for several shortcomings of previous port impact studies in the estimation of primary port economic impact. These shortcomings are found to create the potential for both positive and negative bias. Also presented in this paper is a technique for circumventing several practical problems in the estimation of secondary economic impact. These adjustments are applied to estimate the economic impact of the Port of Hampton Roads, Virginia.     

Stability of a nonlinear red tide dynamic model in a polluted environment

We develop a nonlinear red tide dynamic model to study the effect on a system of two harmful phytoplankton and zooplankton and of a toxicant emitted into the environment from external sources and a toxin excreted by phytoplankton. We use modern nonlinear dynamics to discuss stability and bifurcation, and obtain the thresholds of persistence and extinction for each species. Numerical simulations are used to validate the theoretical results. The results show that a sequence of Hopf bifurcations occur at the interior equilibrium as the delay increases or the growth rates increase.     

Mechanical Performance of a Vertical Seismic Isolation System Employing a Dish Spring

The base isolation technique has been widely used in different countries to reduce seismic disasters during earthquakes. But most of these devices are effective only in horizontal earthquake responses and do not work well in vertical earthquake responses. We propose a vertical seismic isolation system composed of a dish spring and a visco-elastic damper. To study the stiffness and damping performance of this isolation system, a series of tests under static and dynamic loads were performed. The results show that this system is effective in solving problems related to strong vertical bearing capacity and vertical damping of vertical isolation. The system has not only appropriate vertical stiffness and damper performance, but also excellent mechanical performance. In addition, it is compact, easy to manufacture, and can serve as an ideal vertical damping device.     

The breeding of a winter rye variety with a good eelworm-resistance

Summary Some local varieties of winter rye possess a good eelworm-resistance but have too weak a straw and produce an insufficient quantity of seed on healthy soil or on fields which are slightly infested.On the farm Heertveld, belonging to the C.I.V. Breeding Station, a rye variety has been developed from a cross between Ottersum rye and Petkus winter rye, and it showed a good resistance to the stem eelworm (Ditylenchus dipsaci). The new variety which was included in the Dutch List of Varieties of 1953, distinguished itself by a rapid and good soil coverage and strikingly stiff straw.On investigation by the I.P.O. it was established (after artificial inoculation) that 25% of the plants of Heertveld rye were not affected, 50% were slightly damaged and 25% were heavily attacked. However, in the field it shows a good resistance, due to a good recovery.At the Breeding Station selection for eelworm resistance and also for other desirable features is continued and at present such progress has been made that the Heertveld rye now approaches the production capacity of Petkus.     

审时度势 把握时机 开创种子工作新局面

随着《中华人民共和国种子法》(以下简称《种子法》)的颁布实施及其相应配套法规的相继出台 ,种子行业将面临激烈的变革 ,原有的格局将被打破 ,并进入重组状态。《战国策》中言道 :“时势者 ,百事之长也。”据此可说明认清行业发展大趋势 ,并遵循客观规律加以利用是制胜的前提。只有这样 ,才能把握机遇 ,迎接挑战 ,立于不败之地。为此 ,对种子行业的发展趋势做一些分析。1　中小型经营单位的发展方向和出路所谓中小型经营单位是指经营种子量在 5 0万～15 0万千克 ,制种基地在 5 0 0 0亩左右 ,并拥有一定数量固定客户和市场 ,但缺乏自己拳头…     

Characterization of a male sterile mutant from progeny of a transgenic plant containing a leaf senescence-inhibition gene in wheat

A male sterile plant of wheat (Triticum aestivum L.) segregated from progenies of a transgenic family containing the leaf senescence-inhibition gene P _SAG12 -IPT in the genetic background of ??Xinong 1376??, a well adapted winter wheat cultivar. The male sterile plant (named TR1376A) showed no phenotypic changes, except for florets and male organs, compared to its male fertile sibling plants (named TR1376B). The glumes and florets of male sterile TR1376A plants widely opened whereas those of the fertile counterpart TR1376B were closed or opened only briefly at flowing. Anthers of TR1376A were slender and indehiscent, and failed to release pollen. Compared to TR1376B, TR1376A anthers contained greatly reduced amounts of pollen, which was inviable or weakly viable. Ultra-structure studies indicated that cells in the endothecium and middle layers of the anther wall were dissolved or poorly developed in the sterile anthers of TR1376A. Molecular studies showed that the male sterility of TR1376A was caused by a sequence deletion or mutation that occurred in the promoter region of the transgene. F₁ hybrids of TR1376A and TR1376B gave 1:1 segregation of male fertility to sterility, indicating that the male sterility of TR1376A was heritable and controlled by a single dominant gene (named Ms1376). To date, only a few dominant nuclear male sterility genes have been characterized and one of them (Ms2) has been successfully used to improve wheat cultivars through recurrent breeding strategies. The discovery of the Ms1376 gene provides another dominant male sterile source for establishing recurrent breeding systems in wheat.     

The use of a modified bulk segregant analysis to identify a molecular marker linked to a scab resistance gene in apple

Almost two-hundred random sequence decamer-primers were used to screen a pair of bulked samples and the donor parent Malus floribunda clone 821 for markers linked to the V_f gene conferring resistance to apple scab (Venturia inaequalis (Cke.) Wint.). A single primer was identified which generated a PCR fragment, OPK16/1300, from the donor parent M. floribunda clone 821 and the scab-resistant selections/cultivars bulk, but not from the scab-susceptible recurrent parent bulk. Co-segregation analysis using a segregating apple progeny and polymorphism analysis of individual scab-resistant Coop selections/cultivars confirmed that this marker was linked to the scab-resistance gene V_f with a recombination frequency of 4.3%. OPK16/1300 was then cloned and sequenced. Sequence-specific primers of 25 oligonucleotides based on the marker were synthesized, and used in turn to screen M. floribunda clone 821, scab-susceptible apple cultivars, scab-resistant apple cultivars, and scab-resistant Coop selections. A pair of sequence-specific primers of clone OPK16/1300 amplified a distinct single band of the same size as the RAPD clone. Thus, a sequence characterized amplified region (SCAR) marker was developed which can be used to identify polymorphisms of OPK16/1300 based on the presence or absence of a single band. This revised version was published online in July 2006 with corrections to the Cover Date.