几类叶面肥对金华大白桃果实经济性状的影响

[目的]筛选有助于增进金华大白桃品质的叶面肥和生长调节剂。[方法]研究7种叶面肥和生长调节剂对金华大白桃果实主要经济性状以及生长发育的影响。[结果]幼果期适时喷施福施壮和S-诱抗素后,大白桃单果重、可溶性固形物含量等果实主要经济性状显著高于对照,并明显优于其他处理。活清浇施处理明显提高了金华大白桃的品质。[结论]喷施福施壮、S-诱抗素和浇施活清对提高金华大白桃品质作用明显,适合在生产上推广应用。     

Variation for agronomic and processing traits in Solanum tuberosum haploids × wild species hybrids

Summary The broad range of wild and cultivated species relatives of the commerical potato (Solanum tuberosum L.), guarantees the existence of a gene reservoir to be screened for traits that are absent or present only in low frequencies in the cultivated germplasm. Haploids (2n=2x=24) extracted from the cultivated tetraploid (2n=4x=48) germplasm cross easily with diploid (2n=2x=24) potato species and produce fertile progeny. As most haploid × species hybrids tuberize under long day conditions they can be maintained clonally and evaluated for the traits of interest. Three populations involving Tuberosum haploids × Solanum bukasovii (tub x buk), Tuberosum haploids × Solanum sparsipilum, (tub × spl) and Tuberosum haploids × Solanum berthaultii (tub x ber) clones, were planted at two locations in Wisconsin. The haploids were derived from W231, a selected clone from the University of Wisconsin Potato Breeding Program. The objectives were: to evaluate the H-S populations for agronomic and processing traits, and to determine the phenotypic associations between them. Data were recorded on haulm maturity (HM), tuber weight (TW) and tuber number (NT) per plant, specific gravity (SG), chip color after harvest (CH), and chip color after storage at 4° C and one week of reconditioning at room temperature (CH1). Results for SG and CH indicated good potential of the germplasm evaluated to introgress these traits into the commercial potatoes. For instance, the SG mean for tub x buk, tub x spl and tub x ber were 1.079, 1.086 and 1.082, respectively, and their means for CH were 4.8, 3.9 and 3.5. Chip color after storage and reconditioning was found in low frequency in the populations. Four clones in the tub x spl population, and three clones in the tub x ber population had CH1 4.0, the commercially acceptable score for this trait. Significant (p 0.01) phenotypic correlations (r) were found between HM and SG (r=–0.46 in tub x buk, r=–0.61 in tub x spl, and r=–0.34 in tub x ber), NT and TW (r=0.79 in tub x buk, r=0.88 in tub x spl, and r=0.71 in tub x ber), and TW and SG (r=0.40 in tub x buk, and r=0.36 in tub x spl). The correlation coefficients between processing traits were not significant, which may indicate the presence of separate genetic mechanisms governing the inheritance of these traits.     

Beyond occurrence: Body condition and stress hormone as integrative indicators of habitat availability and fragmentation in the common toad

Availability and fragmentation of habitat are today identified as key determinants of population maintenance. Disentangling their relative effects is of crucial importance to adequately manage landscapes. However, the classical use of occurrence or abundance data as proxy to assess the responses of populations could be insufficient to detect less drastic impacts than short-term population extinction. We evaluated the effects of both habitat availability and fragmentation at three spatial scales on both the occurrence and two “physiological state” indicators (body condition and level of stress hormone) reflecting the physical state of common toads (Bufo bufo). Our study showed that occurrence was negatively affected only by habitat availability at the largest spatial scale whereas the both physiological state indicators studied at the population scale are significantly altered by both habitat availability and fragmentation at the finest spatial scale. Results obtained with occurrence and physiological state approaches substantially diverge, which highlights the need to also investigate proximal processes to deeply understand how populations are threatened by landscape modifications. The use of physiological state indicators, particularly of body condition, powerful and easy to obtain, could be particularly relevant to detect early warnings of population decline allowing a management before extinction. Only a complete investigation of the potential impacts of landscape on the different population processes could offer a realistic picture of the requirements of populations to avoid drastic alterations.     

Are rhododendron hybrids distinguishable on the basis of morphology and microsatellite polymorphism?

Sequence Tagged Microsatellite Sites (STMSs) and morphological trait markers were used to evaluate 33 rhododendron germplasm for genetic diversity assessment and discrimination power. The average genetic diversity estimates were 0.724 (morphological traits) and 0.174 (STMSs) marker datasets. The Shannon index was higher for morphological traits (1.797) than STMS (0.302). The correlation coefficients obtained by the Mantel matrix correspondence test, which was used to compare the cophenetic matrices for the two markers, showed that estimated values of relationships given for morphological and STMS were not significantly related (p > 0.05). The dataset from STMS, supported by the total probability of identity (1.13 × 10⁻⁹) and total paternity exclusion probability (0.9999), allowed all accessions to be uniquely identified. In summary, STMS marker proved to be an efficient tool in assessing the genetic variability among old broad leaf rhododendron genotypes. The pattern of variation appeared to be consistent, and it can be used for germplasm conservation and management for restoration of historical genetic resources.     

贵州本地山羊STAT5A基因多态性及其与生长性状关联分析

本研究通过探讨STAT5A基因SNP与山羊生长性状关联性,旨在为山羊选种选育提供更好的科学依据。实验以贵州白山羊和贵州黑山羊为研究对象,采用DNA池法及PCR-SSCP技术检测STAT5A基因单核苷酸多态性。结果发现,在贵州白山羊和贵州黑山羊STAT5A基因内含子10均检测到1个SNP位点G127A,表现为3种基因型,分别命名为GG、GA和AA。基因型与生长性状关联分析显示,贵州黑山羊基因型GA个体的胸围和体重指标显著高于基因型GG个体（p〈0.05）,而其余3个指标均差异不显著（p〉0.05）;贵州白山羊基因型GA个体的体斜长、胸围和管围指标显著高于基因型GG个体（p〈0.05）,而其余指标均差异不显著（p〉0.05）。研究结果提示：STAT5A基因可能是影响山羊体重、体斜长、管围和胸围的主效基因或与主效基因连锁,G127A位点可望作为提高山羊个体生长性状的分子遗传标记。     

干旱胁迫下叶面喷施甜菜碱对番茄幼苗生理指标的影响

在干旱胁迫条件下,叶面喷施一定浓度甜菜碱后,与对照相比,番茄幼苗体内的脯氨酸含量增加,丙二醛含量减少,相对电导率变小,干物质的积累增加.这表明叶面喷施甜菜碱可以提高番茄幼苗的抗旱性,并且以50 mg/L浓度处理最好.