The influence of herbicides on the soil microflora in a plum orchard

The effects of 2.5, 5.0 and 7.5 kg ha^?1 of simazine, atrazine, diuron and bromacil, and 2.0, 3.0 and 4.0 kg ha^?1 of terbacil on the soil microflora was studied in the soil of a plum orchard. A stimulatory effect on the bacterial population and an inhibitory effect on actinomycetes was observed under all the herbicidal treatments up to 60 days from application. Thereafter, the effect levelled off. An inhibitory effect on fungi was noticed with diuron, bromacil and terbacil, but a promotive effect with simazine and atrazine. In general, the herbicide effect lasted up to 60 days and the microbial status of the soil was not significantly disturbed at low and medium concentrations.     

S-RNase based S-genotyping of Japanese plum (Prunus salicina Lindl.) and its implication on the assortment of cultivar-couples in the orchard

Determination of the genetic compatibility between self-incompatible cultivars is crucial in agriculture. The Rosaceae family carries the S-RNase-mediated gametophytic self-incompatibility (GSI) system. Each haplotype is conferred by an S-locus. The S-locus contains two highly polymorphic genes, S-RNase and SFB, which are characteristic of each haplotype and therefore these genes are ideal markers for molecular S-genotyping. In this study 43 Japanese plum cultivars grown in Israel were S-genotyped based on their S-RNase gene sequences. Four alleles, S^b, S^c, S^e and S^h are widespread and together are responsible for 87% of the S-haplotypes therefore many of the cultivar combinations are semi-compatible. In Israel semi-compatibility was shown to correlate with low yield. However, two cultivars, ‘Wickson’ S^fS^k and ‘Shiro’ S^fS^g carry rare S-haplotypes and, therefore, are fully compatible with most of the analyzed cultivars.     

新型叶面肥在李树上的应用效果

为了测试新型叶面肥雄牛牌系列液体肥料对李树的应用效果,以绥李3号为试材,对其在李树上的应用效果进行了研究.结果表明:经雄牛系列液体肥料2号药剂处理的李树的单果重比对照提高10.6 g ;株产量比对照增加4.5 kg ,种植密度按1500株?hm‐2计算,增产6750 kg?hm‐2,增幅达58%,增产效果极佳.     

七个李品种在张掖沙荒地的引种栽培试验

从新疆奎屯果树研究所引进“绥李3号”、“奎冠”、“奎丰”、“奎丽”、“绥棱红李”、“大黄李”等11个品种,对其果实经济性状、生长结果习性、物候期、树体适应性与抗逆性等进行了研究.结果表明:筛选出适合张掖栽培的优质李品种7个,并进行了物候期和果实性状比较,为张掖地区乃至同类地区沙荒地上发展李产业提供理论依据及适用技术.     

新疆野生樱桃李扦插繁殖不定根的形成及生长调节剂对扦插成活率的影响

利用扦插繁殖研究新疆野生樱桃李绿枝扦插的生根机制及不同生长调节剂处理对硬枝扦插生根的影响。结果显示:扦插前,新疆野生樱桃李的茎中没有根原始体细胞,属于诱导型生根。其生根形式主要是愈伤组织生根和皮部生根。绿枝扦插生根包括切口处愈伤组织的形成、根原基的形成和不定根的发育3个过程。愈伤组织由形成层细胞分裂形成,并对不定根的形成起诱导和促进作用;不定根原基起源于形成层,发生部位是形成层与韧皮部射线相交叉的区域。外源生长素类生长调节剂能够促进硬枝扦插的成活率,其中IBA+NAA(1∶1)2 000mg/L蘸根处理插条成活率为30.2%,并且蘸根处理时间以20s为宜。生长调节剂处理后平均根数、平均根长和平均根径变化不大,但平均生根率与成活率的关系密切,说明生长调节剂主要诱导不定根的形成,对根后期发育影响不大。     

4个美国李品种在沾益的引种成效

2000年沾益县自山东农学院果树研究所引入美国大红玫瑰、碧绿红心、美蓝宝石、卡特丽娜4个李品种试种。经过4年的栽培试验，评选出生长好、抗性强，具有丰产、稳产、晚熟性能，果大、质优商品性状好，适宜在沾益及相似生态区域栽培的大红玫瑰、碧绿红心、美蓝宝石3个李品种。     

槜李的生物学特性及栽培技术

介绍珍稀名果——槜李的生物学特性，着重对槜李的定植、定干、各时期树体管理、疏花疏果、肥水管理及主要病虫害防治等关键技术进行了详细介绍。     

Evidence that subsistence farmers have domesticated indigenous fruits (Dacryodes edulis and Irvingia gabonensis) in Cameroon and Nigeria

Ten fruit and kernel traits were measured in 152 Irvingia gabonensis and 293 Dacryodes edulis trees from 6 villages in Cameroon and Nigeria. Frequency distribution curves were used to examine the range of variation of each trait of each species in each village and aggregated into national and regional populations. There were differences between the village sub-populations, with regard to the normality (e.g., mean kernel mass of D. edulis) or skewness (e.g., mean flesh depth of D. edulis) of the distribution curves and in the degree of separation between the individual village populations along the x axis, resulting in the development of a bimodal distribution in the regional population. For all traits, populations of both species differed significantly between countries, but only in D. edulis were there significant differences between the Cameroon populations. On the basis of the results of this study, D. edulis can be said to be virtually wild in Nigeria but semi-domesticated in Cameroon, while I. gabonensis is wild in Cameroon and semi-domesticated in Nigeria. These results are discussed with regard to a hypothesis that the range and frequency of variation in the different populations can be used to identify five stages of domestication. From a comparison of the frequency distribution curves of desirable versus undesirable traits, and statistically identifyable changes in skewness and kurtosis, it is concluded that as a result of the farmers’ own efforts by truncated selection, D. edulis is between Stages 2 and 3 of domestication (with a 67% relative gain in flesh depth) in Cameroon, while I. gabonensis in Nigeria is at Stage 2 (with a 44% relative gain in flesh depth). In this study, genetic diversity seems to have been increased, and not reduced, by domestication. This revised version was published online in June 2006 with corrections to the Cover Date.     

李树不同品种花粉生活力研究

采集盖县大李、澳洲琥珀、长里15号、龙园秋里、大石早生、黑宝石等6个李树品种成年树木花粉,用附加不同浓度蔗糖和硼酸的培养基培养花粉,测定花粉生活力,比较不同品种间花粉生活力差异。结果表明,花粉均在5%蔗糖浓度下发芽率最高,为18.4%,黑宝石发芽率最高。     

李ISSR反应体系的优化

以李品种杏梅(hybrid)和斯顿莱(Prunus domestica)为试材，研究了PCR反应体系的主要成分及退火温度对李ISSR扩增结果的影响。结果表明：在20μl的反应体系中，模板DNA含量对扩增结果影响不大，在10—80ng均能得到较好的扩增；椰用量对扩增无明显影响；而Primer、Mg^2 的最适浓度分别为0．25μmol／L、0.25mmol/L；Taq酶在0．5～1．0U均能得到好的扩增条带；退火温度在50-52．1℃范围内均能得到清晰的条带。