The European Prunus mapping project Progress in the almond linkage map

Summary Six European research groups are collaborating to develop genetic markers and linkage maps for use inPrunus breeding programmes. A basic map with 200 RFLPs and 50 more markers including isozymes and RAPDs will be constructed using two highly segregating populations: an interspecific peach × almond F₂ and a cherry F₂. Then, the parents of eleven almond, cherry, peach or plum breeding progenies segregating for target characters will be screened for polymorphisms at the marker loci, and a set of reduced maps, one per progeny, will be constructed with markers spaced 20–30 cM and covering the whole genome. Cosegregation analysis of markers and characters of interest will allow us to find linkages between markers and major genes or quantitative trait loci responsible for the expression of these traits. A map with 72 markers, 7 isozymes and 65 RFLPs, has been developed at the IRTA-Cabrils laboratory using an intraspecific almond progeny, ‘Ferragnes’ × ‘Mono’. Probes for the analysis of RFLPs were obtained from almond genomic and cDNA libraries. The level of polymorphism for RFLPs and the distribution of markers in the chromosomes of almond are discussed.     

'Francolí', a late flowering almond cultivar re-classified as self-compatible

To verify the compatibility behaviour of the almond cultivar ‘Francolí’ and to clarify its S genotype a combination of pollination tests, stylar ribonuclease and allele specific PCR analysis was used. ‘Francolí’ was released from IRTA's breeding programme in 1994, having been putatively raised from the cross ‘Cristomorto’ (S₁S₂) × ‘Gabaix’ (S₁₀S₂₅). This cultivar was also reported to be self‐incompatible but revealing only one S band in the zymograms after S‐RNases analysis. ‘Francolí’ sets nuts after test crossing with two S₁S₂₅ cultivars, having a different genotype from that earlier reported. ‘Francolí’ was also observed to be self‐compatible after selfing flowers in the field and in the laboratory. ‘Francolí’ was re‐assigned the S₁S_f genotype after test crossing, stylar ribonuclease and PCR data analysis. After microsatellite analysis, the self‐compatible ‘Tuono’ (S₁S_f) cultivar is suggested as the male parent of ‘Francolí’ instead of the earlier reported ‘Gabaix’.     

A major gene for flowering time in almond

Almond (Prunus amygdalus Batsch) is the earliest temperate fruit species to bloom. This restricts the economic growing of almond to frost free regions. Most almond-breeding programmes aim to develop lateflowering cultivars in order to avoid frost damage and take advantage of higher temperatures which are favourable for pollination and fertilization. Flowering time is generally considered to be inherited quantitatively but a single gene conferring very late flowering in a qualitative way has been identified in several progenies tracing back to a single mutant, ‘Tardy Nonpareil’. The effect of this allele has been studied in three progenies, showing that the effect of this major gene is modified by minor genes, quantitatively inherited, and probably influenced by inbreeding.     

Genetic mapping of a major gene delaying blooming time in almond

The objective of this study was to determine the genetic basis of late blooming in almond. Molecular markers were used to study the Late bloom gene (Lb), responsible for a delay of blooming time, in an F₁ segregating population of 134 plants. Using a qualitative approach, the Lb gene was located on linkage group 4 of the almond map, flanked by markers AG6 and FG3. The quantitative analysis confirmed the presence of a major gene on linkage group 4, which explained at least 79% of the phenotypic variation. On average, the plants with the Lb allele bloomed 15 days later and the Lb allele showed dominant gene action. In addition, three RAPD markers associated with the Lb gene were identified by bulked segregant analysis. One was placed at 5.4 cM from Lb and could be used as a diagnostic marker for flowering time.     

Comparison of homozygous and heterozygous self-compatible seedlings in an almond breeding programme

Homozygous self-compatible almond cultivars have not been reported. It is unclear if they are more inferior than heterozygotes or simply have not yet been detected. To investigate if homozygous individual are generally inferior, the self-compatibility genotype, homozygous or heterozygous, was determined by stylar ribonuclease assay in a population of 241 almond trees obtained by self-fertilisation of self-compatible selections. The resulting zymograms showed that 129 of the seedlings were homozygous and 112 heterozygous. For three years the differences observed between these two classes of self-compatible individuals were analysed with respect to 16 agronomic characteristics. In general, there were no important differences between the two classes. Both showed a low degree of productivity, probably as a result of their inbred origin. Some selected homozygous individuals were used in crosses, which were planned so as to ensure the self-compatibility of 100% of the descendants and to eliminate the laborious task of testing the seedlings for self-compatibility. This revised version was published online in August 2006 with corrections to the Cover Date.     

扁桃棉花间作对棉花产量及影响因素的研究

摘要：以大田棉花为对照（CK）,与20年生扁桃树下间作棉花的光合特性、产量及土壤养分进行比较研究,结果表明：①扁棉间作对棉花的产量影响很大,主要表现在间作减少了亩株数、亩铃数和单株成铃数,进而影响到了子棉和皮棉的亩产,扁桃树树冠内侧、树冠外侧2米处的子棉平均亩产分别较对照递减了66.92%和42.78%。②扁棉间作改变了棉花光合特性的日变化规律,对照棉花的光合作用的日变化规律都呈双峰曲线,而间作棉花的变化规律都呈单峰曲线,峰值出现时间早晚与树影变化长度和方向有关。③扁棉间作降低了距离树干5米处（垂直树冠外围附近）土壤水解性氮、有效磷、速效钾、有机质的含量,而对其它各处土壤养分含量的影响不大。说明扁棉间作系统中光合作用是决定棉花产量的最重要因素。     

Correlation of ribonuclease zymograms and incompatibility genotypes in almond

Proteins were extracted from styles of 29 self-incompatible cultivars of almond and separated using non-equilibrium pH gradient electro-focusing, and the gels were stained for ribonuclease activity. Mutually incompatible cultivars had similar banding patterns and, for the 24 cultivars already genotyped in France or California, the bands correlated well with the reported alleles. The band corresponding to S₁ of the French labelling system was indistinguishable from that corresponding to S_b of the Californian labelling system, and a controlled cross confirmed that these alleles are identical. The band corresponding to the Californian S_a was distinct from the bands corresponding to French alleles and, to harmonise the allele labels, it was redesignated S₅. The genotypes of five uncharacterised self-incompatible cultivars were inferred from zymograms as follows: ‘Desmayo Largueta’ and ‘Glorieta’, S₁S₅, ‘Masbovera’, S₁S₉, ‘Tarragones’, S₂S₉, and ‘Tokyo’, S₆S₇. The alleles designated S₆ and S₉ have not previously been reported. Nine self-compatible cultivars or selections were analysed, and each showed a band corresponding to an incompatibility allele as well as a common band; however, the correspondence of this common band to S_f, the allele for self-compatibility, is unproven. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification and characterization of new S‐alleles associated with self‐incompatibility in almond

Almond is a highly heterozygous species with a high number of S‐alleles controlling its gametophytic self‐incompatibility system (GSI). In this work, we have analysed 14 Spanish local almond cultivars for S‐RNase allele diversity. Five new S‐RNase alleles were identified by cloning and sequencing, S₃₁ (804 bp) in ‘Pou de Felanitx’ and ‘Totsol’, S₃₂ (855 bp) in ‘Taiatona’, S₃₃ (1165 bp) in ‘Pou d’Establiments’ and ‘Muel’, S₃₄ (1663 bp) in ‘Pané‐Barquets’ and S₃₅ (1658 bp) in ‘Planeta de les Garrigues’. Additionally, seven already known almond alleles could be recognized in the local cultivars studied. The high number of new alleles identified reveals the wide diversity of almond germplasm still existing and requiring characterization, and points to the possibility of new findings by a wider study focusing on other provenances. The almond S‐RNases have been compared to those of other Prunus species, showing a high identity and confirming that the S‐RNase gene in this genus presents a probable common ancestor.     

On genetically remodeling the almond tree

Summary Dwarf peach trees require only 1/4th the space of standard trees and thus reduce the cost of experiments in which the tree is the experimental unit, by 75%. Or, put another way, they facilitate estimates of tree performance, in experiments of the same size, that are 50% more precise than those obtainable from standard trees. The objective of this study was to determine if the almond tree could be genetically compressed (dwarfed) to facilitate discrimination of genetic and cultural manipulation on its productivity, to facilitate genetic manipulation, and to increase its productive efficiency.The results obtained indicate the almond tree can be dwarfed (compressed), by the dw gene of peach. interspecific crosses of dwarf (dw/dw) peach, P. persica, with almond, P. amygdalus, followed by backcrosses to almond revealed: 1. Plant stature and node density vary widely among the dwarf (dw/dw) inter species hybrids. The heritabilities of these traits are high. 2. Spur density also varies widely. Its mean is high and its heritability is very high. 3. The dwarf inter species hybrids produce flowers copiously. However, at 22 months of age the flowers of most seedlings are sterile, apparently due to abnormal pistils. Consequently, average productivity is very low. However, some of these dwarf P. persica × P. amygdalus hybrids do express moderate to high productivity. Further, the heritability of productivity, among the seedlings expressing some degree of fertility, is very high. Consequently, further backcrosses to almond are expected to rapidly restore fertility and productivity. The yield potential of dw/dw dwarf almonds will remain unknown until fertility is restored.     

The origin of the self-compatible almond 'Supernova'

The almond cultivar 'Supernova' is reported in the literature as a late-flowering self-compatible mutant, obtained by the irradiation of the early-flowering self-incompatible cultivar 'Fascionello'. Our work to investigate the molecular basis of this form of self-compatibility has called into question the origin of 'Supernova'. Test selfing was performed both on 'Supernova' and on the accession of 'Fascionello' from which it was derived –'Fascionello-Rome'. Both proved self-compatible. Amplification of S - RNase alleles, using consensus primers from the signal peptide region to the second conserved region of the S - RNase gene and primers specific for allele S _f , confirmed 'Supernova' and 'Fascionello-Rome' indeed have the same (in)compatibility genotype S ₁ S _f as the self-compatible cultivar 'Tuono'. Nine microsatellite markers were used to fingerprint the relevant accessions; 'Supernova' and 'Fascionello-Rome' were undistinguishable from 'Tuono'. Two Sicilian accessions, 'Fascionello' and 'Falso Fascionello', lacked S _f and differed at the SSR level, indicating no close relationship with 'Supernova'. Therefore we concluded that 'Fascionello-Rome' is actually the same as 'Tuono' and that 'Supernova' originates from 'Tuono' from which it derives its self-compatibility.     

金铁锁生态学初步研究

摘要: 对滇西北及周边部分地区金铁锁野外生态学调查研究结果表明：金铁锁一般出现在海拔2400～3400 m有一定空旷度的砾石或石灰质岩石山坡中;土壤主要为紧实、干燥而贫瘠的石灰岩红壤土或黄砂壤土。对金铁锁分布影响较大的因子是土壤、湿度和温度。对金铁锁生态学特征的了解有助于对它进行人工引种驯化及规范化种植。     

钙营养对温室毛桃果实品质及 生理生化特性的影响

摘 要：以春元、春艳为试材,研究了在温室条件下喷钙对果实品质及生理生化特性的影响。结果表明：与对照相比,喷钙处理提高了果实中Ca2+的浓度,增加了果实中可溶性糖的含量,降低了可滴定酸的含量,增加了可溶性蛋白及Vc的含量,同时提高了POD的活性,降低了PPO的活性,进而改善了果实品质及贮藏性能。     

寒地水稻氮磷钾营养诊断技术的研究

摘要：采用多点田间生物试验法,在2006-2007年对寒地水稻进行了两年营养诊断技术研究,形成了寒地水稻氮、磷、钾的土壤和植株营养诊断技术与方法。氮素诊断在分蘖期和孕穗期均以叶片叶绿素相对含量作为诊断指标最好;磷素营养诊断在分蘖期土壤全磷和植株全磷均可作为诊断指标,在孕穗期以植株全磷为诊断指标最好;钾素诊断在分蘖期土壤速效钾和植株全钾均可作为这个时期的诊断指标,在孕穗期以土壤速效钾进行钾营养诊断最能反映生产实际。     

耐密型玉米育种相关问题的思考

玉米种植密度逐步提高不仅是玉米产量不断提高的主要途径,也是育种中提高选择效果的重要手段。本文结合我国玉米生产和育种的实际情况,对耐密型玉米品种选育的育种目标、种质选择、自交系选育技术和杂交种鉴定技术进行了探讨。     

基于AHP法的物流园区选址模糊综合评判

为了给芜湖市物流园区布局提供规划依据,探讨最佳布局方案,通过分析物流园区选址的各种影响因素,引入层次分析法,建立了芜湖市物流园区选址的综合评价指标体系。最后用模糊综合评判法对方案进行综合评价,最后得出最优的物流园区布局方案。     

华北平原粮田替代型复合种植模式生态 经济比较研究

摘 要：通过定位试验,从生态经济角度对不同间作复合种植模式与传统种植模式进行对比分析,以寻求经济高效、生态安全的替代型种植模式,结果表明：(1)间作改善了作物的生长环境,提高了资源利用率,因而间作复合种植模式间作季节表现出明显的产量优势,间作复合种植模式单作季节产量明显增加。(2)禾豆间作不仅通过直接影响当季作物的产量形成来提高土地利用率,而且还通过对后作作物产量的积极影响来提高后作作物的土地利用率,从而提高复合种植模式整体的土地利用率。研究得出间作复合种植模式土地利用率全年提高了4.0%~7.0%。(3)间作复合种植模式在间作季及全年的农机械、农药、化肥的经济投入量减少,农机械、农药等措施的减少,降低了对农田土壤理化性状等的外来干扰,这对改善农田生态环境来说意义重大。(4)间作复合种植模式提高了各季及全年的经济效益和经济产投比。全年经济效益最高可达25067.7元/hm2,比对照提高了18.97%。综合以上结果,从改善农田生态、提高资源循环利用效率与提高经济效益等方面整体评价,禾豆间作复合种植模式可以作为传统麦玉连作的替代模式之一。     

普通野生稻抗旱性初探

摘要：以普通野生稻六个居群（海南琼海居群,万宁居群,儋州居群,文昌居群,乐东居群,长雄野生稻）为材料,在干旱胁迫条件下分别测定其叶片相对含水量、叶绿素含量、叶片游离脯氨酸含量三个生理指标,结果表明,各居群叶片相对含水量均呈下降趋势,且下降幅度不同;叶绿素含量呈“先升后降”趋势;脯氨酸含量呈不同程度的上升。综合三项生理指标及干旱条件下对各居群的实际观察情况,初步认为它们的抗旱性大小顺序如下：琼海居群＞长雄野生稻＞万宁居群＞儋州居群＞乐东居群＞文昌居群。     

基于叶片面积玉米叶片保绿度开花后衰减特性初步研究

摘要：采用Excel工作表及Origin7.0统计分析软件对基于绿叶面积玉米叶片保绿度开花后衰减特性进行了初步研究,结果表明：玉米开花后叶片保绿度衰减符合方程y=aeb-cx/(1+eb-cx);不同基因型玉米叶片保绿度衰减启动时间、最大衰减速率和最大衰减速率出现时间等衰减特性差异较大;即使相同基因型在不同环境条件下叶片衰减特性也不尽相同。采用y=aeb-cx/(1+eb-cx)模拟方程能比较全面揭示叶片保绿度的动态变化过程。     

不同来源腐殖酸对土壤酶活性的影响

本文选用沈阳市东陵区天柱山耕作棕壤,采用室内培养试验研究了不同来源腐殖酸对土壤酶活性的影响情况。研究表明：三种腐殖酸均对脲酶、过氧化氢酶起抑制作用,且以褐煤腐殖酸最突出;对转化酶和中性磷酸酶均有促进作用。其中,风化煤腐殖酸对转化酶活性的促进作用较突出,褐煤腐殖酸对中性磷酸酶活性的促进作用最突出。     

不同类型早熟桃、油桃采后贮藏效果研究

采用不同肉质类型的桃、油桃果实为材料,对采后低温和自发气调包装等对果实硬度、失重和SSC含量等的变化进行了研究,结果表明：(1)不同类型桃、油桃采后果实硬度变化差异较大,常温下24-30和中桃2号果实硬度下降较慢,而中油桃5号、10号较快,在冷库低温条件下,24-30、中油桃5号和中油桃10号两周后硬度出现迅速下降,而曙光和中桃2号在贮藏后即迅速下降,带皮硬度与去皮硬度之间有一定差异,但变化趋势基本一致;(2)MA包装能有效地延缓采后桃、油桃果实硬度的降低,在常温及低温条件下均是如此,不同肉质类型间差异明显,曙光和中桃2号非常敏感,而中油桃10号则不太敏感,即MA包装对其果实硬度降低的延缓没有其它品种明显;(3)采后桃、油桃果实的SSC含量均有一定的降低,低温下该过程较慢,MA包装在常温下有加剧SSC下降的趋势,低温下则不明显,这可能与常温下采后立即进行MA包装不利于“田间热”及呼吸热的及时散发而加剧呼吸有关。(4)桃、油桃采后果实失重明显,低温有助于大大减缓贮藏桃、油桃的失重,常温下1天的失重相当于低温条件下1周的失重,不同类型品种表现有一定差异,常温下曙光失重较慢,而冷库低温条件下中桃2号失重要快于曙光和中油桃10号。