Effect of crop load on hardiness,protein and amino acids content of apple flower buds at the wintering stage and the begining of the growth∗

The cold tolerance of flower buds of apple Malus domestica Borkh. ('Mclntosh'/M.7) declined during spring growth. The absence of fruit in the previous year increased the ability of the buds to withstand lower temperatures. All flower buds retained the capacity to tolerate freezing injury until first pink stage. The median lethal temperature (MLT) of the flower buds increased relatively throughout the sampling period. The flower buds of cropped trees were more susceptible to low temperature injury during spring at all stages of development. The flower buds of non‐cropped trees contained higher levels of hydrophilic and acidic amino acids from October until April, which may be related to their greater cold tolerance. A new nitrogen:protein conversion factor (5.51) was calculated based on total amino acid analysis which could be substituted for 6.25 as a means of estimating total protein content of apple flower bud tissue using the Kjeldahl method.     

For how long does the quality and quantity of residues in the soil affect the carbon compartments and CO<Subscript>2</Subscript>-C emissions?

Purpose

The mineralization/immobilization of nutrients from the crop residues is correlated with the quality of the plant material and carbon compartments in the recalcitrant and labile soil fractions. The objective of this study was to correlate the quality and quantity of crop residues incubated in the soil with carbon compartments and CO₂-C emission, using multivariate analysis.

Materials and methods

The experiment was conducted in factorial 4?+?2?+?5 with three replicates, referring to three types of residues (control, sugarcane, Brachiaria, and soybean), and two contributions of the crop residues in constant rate, CR (10 Mg ha^?1 residue), and agronomic rate, AR (20, 8, and 5 Mg ha^?1 residue, respectively, for sugarcane, soybean, and Brachiaria), evaluated five times (1, 3, 6, 12, and 48 days after incubation). At each time, we determined the CO₂-C emission, nitrogen and organic carbon in the soil, and the residues. In addition, the microbial biomass and water-soluble, labile, and humic substance carbons fractionated into fulvic acids, humic acids and humin were quantified.

Results and discussion

Higher CO₂-C emissions occurred in the soil with added residue ranging from 0.5 to 1.1 g CO₂-C m^?2 h^?1 in the first 6 days of incubation, and there was a positive correlation with the less labile organic soil fractions as well as residue type. In the final period, after 12 days of soil incubation, there was a higher relation of CO₂-C emission with carbon humin. The sugarcane and soybean residue (20 Mg ha^?1) promoted higher CO₂-C emission and the reduction of carbon residue. The addition of residue contributed to an 82.32 % increase in the emission of CO₂-C, being more significant in the residue with higher nitrogen availability.

Conclusions

This study shows that the quality and quantity of residue added to soil affects the carbon sequestration and CO₂-C emission. In the first 6 days of incubation, there was a higher CO₂-C emission ratio which correlates with the less stable soil carbon compartments as well as residue. In the final period of incubation, there is no effect of quality and quantity of residue added to soil on the CO₂-C emission.

     

Microsatellite genotyping of apple (<Emphasis Type="Italic">Malus</Emphasis> × <Emphasis Type="Italic">domestica</Emphasis> Borkh.) genetic resources in the Netherlands: application in collection management and variety identification

A highly informative set of 16 microsatellite markers was used to fingerprint 695 apple accessions from eight Dutch collections. Among the total sample, 475 different genotypes were distinguished based on multi-locus microsatellite variation, revealing a potential redundancy within the total sample of 32%. The majority of redundancies were found between collections, rather than within collections. No single collection covered the total observed diversity well, as each collection consisted of about 50% of unique accessions. These findings reflected the fact that most collection holders focus on common Dutch varieties, as well as on region-specific diversity. Based on the diversity patterns observed, maintenance of genetic resources by a network of co-operating collection holders, rather than by collecting the total diversity in a single collection appears to be an efficient approach. Comparison of microsatellite and passport data showed that for many accessions the marker data did not provide support for the registered variety names. Verification of accessions showed that discrepancies between passport and molecular data were largely due to documentation and phenotypic determination errors. With the help of the marker data the varietal names of 45 accessions could be corrected. Microsatellite genotyping of apple appears to be an efficient tool in the management of collections and in variety identification. The development of a marker database was considered relevant as a reference instrument in variety identification and as a source of information about thus far unexplored diversity that could be of interest in the development of new apple varieties.     

Identification of unknown apple (<Emphasis Type="Italic">Malus</Emphasis> × <Emphasis Type="Italic">domestica</Emphasis>) cultivars demonstrates the impact of local breeding program on cultivar diversity

Apple (Malus?×?domestica Borkh.) trees, either abandoned or cared for, are common on the North American landscape. These trees can live for decades, and therefore represent a record of large- and small-scale agricultural practices through time. Here, we assessed the genetic diversity and identity of 330 unknown apple trees in northern Minnesota with 9 simple sequence repeat (SSR) markers. The unknown (not identified by cultivar name) trees were compared to >?1000 named cultivars in the U.S. Department of Agriculture Plant Genetic Resources Unit Malus collection and also to each other to identify repeated genotypes. Overall, the 330 unknown trees had high diversity (average H_e?=?0.75), and consisted of 264 unique genotypes. A total of 76 of the unknown trees were matched to 20 different named cultivars, and these cultivars were mainly derived from either the local breeding program at the University of Minnesota, or were Russian cultivars imported for horticulture in the northern US. This study demonstrates the importance of local breeding programs, and also the challenges associated with identifying clones in a genetically diverse crop like apple.     

Genetic identity and relationships of Iranian apple (Malus?×?domestica Borkh.) cultivars and landraces, wild Malus species and representative old apple cultivars based on simple sequence repeat (SSR) marker analysis

In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25 alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics, gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major players in apples’ domestication and transfer from Central Asia to the western countries.     

Effects of vesicular‐arbuscular mycorrhizas and phosphorus on water status and growth of apple

Apple (Malus hupehensis Rehd) seedlings were grown in sterilized and non‐sterilized soil with or without phosphorus (P) added and inoculated by VA mycorrhizal (VAM) fungi (Glomus versifome Daniels et Tappe and Glomus macrocarpum Tul et Tul). In sterilized soil, the VAM infection increased the transpiration rate (Tr.) of the leaves, reduced the stomatal resistance (Sr.) and the permanent wilting percentage (PWP) and enhanced the rate of recovery of the plant from the water stress and the plant growth (e.g. leaf number, stem diameter and dry weight). It also increased absorption of most minerals, especially Zn and Cu by the roots and weakened the P‐Cu and P‐Zn interactions. Phosphorus fertilization had some positive effects on the water status, P nutrition and growth, but it reduced the Cu concentration. VAM improved the water status and enhanced drought tolerance of the trees by enhancing absorption and translocation of water by the external hyphae. The efficiency of inoculation in nonsterile soil was not obvious.     

Which polyphenolic compounds contribute to the total antioxidant activities of apple?

The antioxidant activities of eight apple cultivars were studied by using the ferric reducing/antioxidant power (FRAP), the beta-carotene-linoleic acid model system (beta-CLAMS), and the photochemiluminescent (PCL) assays. The antioxidant activity of apples is highly correlated to the total phenolic content (TPC) measured by the Folin-Ciocalteu method and the total polyphenolic index (TPI) obtained by HPLC. Extracts of the peel and flesh were analyzed and assayed separately. The FRAP activities of both peel and flesh extracts correlate well with the TPC (r = 0.95 and 0.99, respectively) and the TPI (r = 0.82 and 0.99, respectively). Similar results were found in the beta-CLAMS activities, showing correlation coefficients of r = 0.90 and 0.91 with the TPC for the peel and flesh extracts and of r = 0.90 and 0.84 with the TPI for the peel and flesh extracts, respectively. The antioxidant activity measured by the PCL assay was not correlated with TPC or TPI due to the lack of integratable lag phase in this method with the flavan-3-ols/procyanidins. Among the five major polyphenolic groups, flavan-3-ols/procyanidins had the highest positive correlation with the FRAP and beta-CLAMS activities: r = 0.84 and 0.88 for the peel extracts, respectively; and r = 0.98 and 0.87 for the flesh extracts, respectively. At individual compound level, epicatechin and procyanidin B2 were the major contributors to the antioxidant activity of apple. Hydroxycinnamic acids may have a significant role in the flesh.     

Identification and relationships of accessions grown in the grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) Germplasm Bank of Castilla y Léon (Spain) and the varieties authorized in the VQPRD areas of the region by SSR-marker analysis

A total of sixty-five accessions from the Spanish region of Castilla y León including those authorized in the VQPRD areas were characterized for six SSR loci. All the samples but one unknown were identified by comparison to other databases. Thirty synonymous samples and three cases of homonymy were found out, confirming in most cases ampelographic expectations. Five unique genotypes belonging to local varieties in risk of extinction were detected. Several parameters were calculated to assess the usefulness of the chosen loci in this work. A dendrogram representing the genetic similarities among the accessions was constructed using the neighbor-joining method to investigate possible parentage relationships in the sample, and to explain them from an historical and cultural point of view.     

Detection and quantification of apple adulteration in diluted and sulfited strawberry and raspberry purées using visible and near-infrared spectroscopy

Adulteration of sulfited strawberry and raspberry purées by apple is a commercial problem. Strawberry (n = 31) and raspberry (n = 30) purées were prepared from Irish-grown fruit and adulterated at levels of 10-75% w/w using cooking apples. Visible and near-infrared transflectance spectra were recorded using a 0.1 mm sample thickness. Classification and quantification models were developed using raw and scatter-corrected and/or derivatized spectral data. Classification as pure strawberry or raspberry was attempted using soft independent modeling of class analogy. The best models used spectral data in the wavelength ranges 400-1098 nm (strawberry) and 750-1098 nm (raspberry) and produced total correct classification rates of 75% (strawberry) and 95% (raspberry). Quantification of apple content was performed using partial least-squares regression. Lowest predictive errors obtained were 11.3% (raspberry) and 9.0% (strawberry). These results were obtained using spectral data in the wavelength ranges 400-1880 and 1100-1880 nm, respectively. These results suggest minimum detection levels of apple in soft fruit purées of approximately 25 and 20% w/w for raspberry and strawberry, respectively.     

Increased phloridzin content associated with russeting in apple (<Emphasis Type="Italic">Malus domestica</Emphasis> (Suckow) Borkh.) fruit

Phloridzin is a phenolic compound unique to apple (Malus domestica (Suckow) Borkh.) and its wild relatives. Since its discovery, phloridzin has been researched for its nutraceutical properties, including anti-diabetic, anti-cancer, and antioxidant activities, making phloridzin a potential target for nutritional improvement in new apple cultivars. However, phloridzin accumulates at significantly lower concentrations in fruit than in vegetative tissues and seeds. In ‘Golden Delicious’ and its sports, we observed higher phloridzin content in peels of sports with a cuticle disorder termed russet. In russeted apples, the smooth, waxy fruit cuticle is partially or entirely replaced by a corky layer, induced through environmental and genetic effects. To understand the variation of phloridzin content and fruit russet in apple fruit, we surveyed 108 accessions with variation in russeting from the USDA-ARS Malus germplasm collection in Geneva, NY. Russeting in apple fruit ranged from 0 to 100%, and phloridzin content ranged from 24.3 to 825.0 μg/g in peels. Mean phloridzin content varied significantly between russeting groups; in groups with light (0–5%), medium–high (70–80%), and high (90–100%) russeting mean phloridzin content was 115.2, 591.2, and 378.8 μg/g, respectively. We observed that genetic factors and russeting are strong predictors of phloridzin content in peels, but not fruit flesh or leaves. Conversely, other peel phenolics are negatively associated with russeting. We observed variable phloridzin content related to russet incidence during fruit development in ‘Golden Delicious’ (low to medium russet) and its sports, ‘Empress Spur’ (low russet), ‘Razor’ (complete russet), and ‘Sergeant Russet’ (medium to high russet).     

Semitic-language records of snake melons (<Emphasis Type="Italic">Cucumis melo</Emphasis>, Cucurbitaceae) in the medieval period and the “piqqus” of the “faqqous”

The snake melon, Cucumis melo subsp. melo Flexuosus Group, is a cucurbit crop that was grown and esteemed in Mediterranean lands in antiquity and classical times. Images of snake melons appear in ancient Egyptian wall paintings and sculptures and in mosaics from the Roman Empire. The sikyos of Greek, the cucumis of Latin, and the qishu’im of Hebrew, thought by many to be cucumbers, Cucumis sativus, have now been identified as snake melons. Less iconographic and written evidence exists concerning the appreciation of snake melons during the medieval period. The present work focuses on some philologically based evidence of the importance of snake melons leading into and including the medieval period, with two specific objectives. One was to trace the records of the Hebrew epithet piqqus, which applied to removal of the hairs of young cucurbit fruits, and the Arabic epithet faqqous, used historically and to the present day to designate snake melons. Another objective was to re-affirm how piqqus was actually conducted, as mandated in the second-century code of Jewish Oral Law known as the Mishna. Various conjugational forms of the Hebrew word piqqus were found in writings dating from 200 CE to approximately 600 CE. Evidence is presented that further establishes the exact meaning of piqqus as the rubbing off of the hairs of young cucurbit fruits. The Arabic word faqqous was found in writings dating from the beginning of the tenth century and through to the end of the medieval period in the fifteenth century, the writers hailing from Andalusia in the west to Iraq in the east. These writings suggest that the snake melon was a familiar vegetable across a wide geographic belt throughout the medieval period.     

On the trail of the last autochthonous Italian einkorn (<Emphasis Type="Italic">Triticum monococcum</Emphasis> L.) and emmer (<Emphasis Type="Italic">Triticum dicoccon</Emphasis> Schrank) populations: a mission impossible?

In 1970s it was thought that two species of ‘farro’, namely emmer (Triticum dicoccon Schrank) and einkorn (T. monococcum L.), were no longer present in Italy, but in 1981, some populations were discovered in a mountain area of the Appennino Sannita (central southern Italy). In 2006/2007 three monitoring missions were carried out to check the current situation of these ancient hulled wheats, specifically in the same areas where they were formerly collected. The same zones were also investigated by both paleo-ethnobotany and agrobiodiversity points of view. The results of this research have shown that nowadays einkorn is completely extinct while emmer is still cultivated in very few traditional farms, mainly as a fodder crop. A strong genetic erosion was detected also for emmer and several nowadays samples were contaminated by seeds of modern spelt (T. spelta L.) varieties. In the present study the causes of this genetic erosion and which safeguarding actions to be undertaken are discussed.     

Spatial and vertical distribution of <Superscript>137</Superscript>Cs in soils in the erosive area of southeastern Serbia (Pčinja and South Morava River Basins)

Purpose

The area of southeastern Serbia, the P?inja and South Morava River Basins, is under the influence of very strong erosion, and the aim of this study was to investigate the vertical and spatial distribution of the ¹³⁷Cs in the eroded soils of this area.

Materials and methods

Vertical soil profiles were collected with 5-cm increments from the uppermost layer down to 20, 25, 30, 40, and 50 cm of depth, depending on the thickness of the soil layers, i.e., down to the underlying parent rocks. Measurements of ¹³⁷Cs activity concentration were performed by using the HPGe gamma-ray spectrometer ORTEC-AMETEK (34 % relative efficiency and high resolution 1.65 keV at 1.33 MeV for ⁶⁰Co), from its gamma-ray line at 661.2 keV.

Results and discussion

The mean ¹³⁷Cs activity concentration across all 18 soil profiles (for all soil layers) was found to be 20 Bq kg^?1. In the greatest number of soil profiles, the ¹³⁷Cs activity concentration was generally highest in the first soil layer (0–5 cm) and decreased with soil depth, while in a few soil profiles, the peak of either the ¹³⁷Cs activity concentration occurred in the second soil layer (5–10 cm) or the ¹³⁷Cs activity concentration was almost equal throughout the entire soil profile. The mean ¹³⁷Cs activity concentration in the first soil layer (0–5 cm) was found to be 61 Bq kg^?1, and the high coefficient of variation of 92 % pointed out high spatial variability and large range of the ¹³⁷Cs activity concentrations in the study area.

Conclusions

The obtained results indicate that in the greatest number of soil profiles, ¹³⁷Cs is present in the upper layers, with concentration decreasing with depth, as is typical in uncultivated soil. Its spatial distribution was very uneven among the surface soil layers of the investigated sites. One of the main reasons for such pattern of ¹³⁷Cs in the study area may be soil erosion. Additional investigations which would support this hypothesis are required.

     

Review Article. What are the nature and formation conditions of hydroxy‐interlayered minerals (HIMs) in soil?

Primary minerals of the parent material undergo weathering during the formation of terrestrial soils to varying extent. As a result, secondary minerals develop, which comprise, among many others, hydroxy‐interlayered minerals (HIMs). These minerals have formed by interlayering of hydroxy‐metal complexes (especially of Al³⁺, also Mg²⁺, Fe^2+/3+) into micas, expansible 2:1 phyllosilicates and forming oligomers, or by weathering of primary chlorite. The degree of interlayer filling and the stability of these fillings affect several physico‐chemical soil properties, for instance the cation exchange capacity. Although many studies have been conducted on formation, occurrence, and properties of HIMs in soil during the last decades, several challenges still exist. These challenges include analytical identification and quantification of HIMs in soil, the nature of the interlayer filling and the identification of favorable conditions in soil for the formation of HIMs. In order to deepen the understanding of formation, properties, and fate of HIMs in soil, we critically reviewed the available literature. Based on the review, we recommend using a new structural model that enables quantification of hydroxy‐interlayered smectite in soil by X‐ray diffractometry, laboratory experiments on the formation and preservation of different types of interlayers and considering the temporal and spatial dimension of the formation of HIMs in soil in more detail.     

Concentrations and Availability Indicators of Soil Heavy Metals; the Case of Children’s Playgrounds in the City of Athens (Greece)

This study reports on the concentrations, distribution, and availability of heavy metals in the children’s playground soils of Athens. Playgrounds were chosen because they are open city areas; they show relatively even spatial distribution within the district of Athens and are used by a great number of young children and their escorts on a regular basis. Samples were collected from 70 playground surface soils, representing more than 70% of the city’s playgrounds. Cu, Zn, Pb, Cr, Ni, Co, Mn, and Fe were extracted by aqua regia and by diethylene triamine pentaacetic acid (DTPA) to estimate total and available metal forms, respectively. Their mean total concentrations were 43, 174, 110, 80, 82, 22, 312, and 17?×?10³?mg kg^?1, respectively. The DTPA-extracted fraction showed much lower values, with means of 2.5, 7.8, 5.8, 1.5, 1.3, 0.4, 8.4, and 2.0 mg kg^?1 respectively, which, however, should be carefully monitored since they relate directly to the bioavailable fraction of heavy metals. Though mean values of metal concentrations are not particularly high, the calculated enrichment factors indicate site-specific cases of high enrichment with heavy metals. Considering that the bioavailable fraction of a metal is possibly a more appropriate indicator for the recent soil pollution history, availability ratios were calculated and their distribution was visualized over the entire city profile using the appropriate GIS software. It was shown that recent metal pollution events appear to have affected mostly playground sites in the southern and eastern part of the municipality.     

Effect of root pruning and nitrogen fertilization on growth of young ‘fuji’ apple (Malus domestica borkh.) trees

This study examined the effect of root pruning (RP) and nitrogen fertilization (NF) alone or in combination (RP-NF) on growth properties of 3-year-old ‘Fuji’ apple (Malus domestica Borkh.) trees. The results of pot experiments showed that the trees were sensitive to RP and NF alone or in combination in terms of root architecture, leaf photosynthesis, and canopy growth. Compared with the control, NF and RP-NF increased root length density and tips, while RP and RP-NF decreased root surface area and volume. RP alone reduced coarse root length (2.0–4.0 and >4.0 mm diameter), while RP-NF simultaneously increased fine root length (≤1.0 mm diameter) and reduced coarse root length. Moreover, RP increased leaf chlorophyll content and transpiration rate, while RP-NF increased net photosynthetic rate and water use efficiency. RP-NF resulted in no differences in dry matter weight, root-shoot ratio, or leaf area compared with the control. Inhibiting vegetative growth by RP-NF provided an effective way to improve water use efficiency of young apple trees.     

Effects of rootstock and thinning on yield,fruit quality and elemental composition of ‘Redspur Delicious’ apple

Abstract

Influence of two rootstocks and five levels of hand thinning (fruit spacing) on yield, fruit quality at harvest and after storage, and leaf and fruit elemental composition of ‘Redspur Delicious’ apple (Malus domestica Borkh.) were studied. Trees on M.7 rootstock had a higher yield with heavier and firmer fruit at harvest than those on M.26. Trees on M.7 had significantly lower leaf and fruit N which resulted in a darker fruit color than those on M.26 rootstock. Fruit from trees on M.26 had a higher soluble solids concentration (SSC) at harvest than those on M.7. Leaf and fruit potassium (K) increased but fruit calcium (Ca) decreased with an increase in fruit spacing. Thinning fruit to 10 cm or 18 cm spacing, depending on market demand for fruit size, is recommended for improvement of fruit quality. Fruit weight and quality was improved with 18 cm fruit spacing without a significant decrease in yield, while thinning fruit further than 18 cm apart reduced yield without a significant change in the fruit weight or quality.     

Interstock effects on growth,photosynthesis and mineral nutrition of ‘delicious’ apple seedlings

Tree growth, photosynthesis, and the mineral nutrient content were investigated in ‘Redchief Delicious’ scions double worked on seedling rootstock with a variety of interstocks. The interstocks used were ‘Redchief Delicious’, M9, and a range of F. generation hybrids with internodes designated short, medium and long. The long internode graft union consistently produced more growth and dry weight per tree than the other interstocks. The ‘Redchief Delicious’ interstock had an unexplained negative effect on leaf, shoot and new root dry weight. There was no effect of interstock on photosynthesis initially (56 days) however photosynthesis increased with shorter nodal interstocks after 111 days. There were significant differences in scion and interstock bark elemental composition due to interstock combination. However, leaf composition varied slightly among the different interstock combinations. Manganese levels, independent of tissue type, did not vary between interstocks.     

Differentiation among Maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) Landraces from the Tarasca Mountain Chain,Michoacan, Mexico and the <Emphasis Type="Italic">Chalqueño</Emphasis> Complex

The classification of Mexican maize (Zea mays L.) begun since the early 20th century, it was consolidated during the middle of this century, but recent additions and rearrangements have been performed by several authors employing new methods of analysis and collections from diverse origin; nevertheless, maize from the State of Michoacan, Mexico has received little attention in regard to its systematic classification. Maize populations from the Tarasca Mountain Chain in Michoacan are commonly considered in literature, as belonging to the Chalqueño race; however, closer observations indicate that significant differences do exist, suggesting the necessity of performing an in-depth study on this respect. Thirty nine native maize populations from the Tarasca Mountain Chain region were evaluated along with 19 typical populations of the Chalqueño, Celaya and Conico races coming from the States of Mexico, Puebla, Hidalgo, Querétaro and Oaxaca. Populations were evaluated in Aranza, Michoacan and Montecillo, Mexico State. Seventeen morphological characters were scored and analyzed by one-way analyses of variance and multivariate techniques. Populations were also genetically analyzed through 17 isozyme loci. Native populations had some alleles not found either in the Chalqueño, Celaya or Conico races, and possess larger genetic diversity. Local populations were congregated into a discrete group apart from the typical Chalqueño populations, suggesting that landraces from the Tarasca Mountain Chain region might not be considered as belonging to the Chalqueño race, but they integrate by themselves a different race.     

Interstock effects on growth and 45Ca distribution in ‘delicious’ apple seedlings 1

Comparisons were made of the ⁴⁵Ca uptake of ‘Redchief Delicious’ apple seedlings (Malus domestica Borkh) grown on ‘York Imperial’ rootstocks with interstocks of ‘Redchief Delicious’, M9 and short, medium and long internode ‘Delicious’ stocks. Seedlings were grown in aerated complete nutrient solutions. Applied ⁴⁵Ca was readily translocated to rootstocks, interstocks, scions and leaves of M9 and short internode combinations.

⁴⁵Ca accumulated to a much greater extent in rootstock and the interstock than the scion. Applied ⁴⁵Ca was translocated much more readily to the bark than to the wood.