The inheritance of chemical phenotype in <Emphasis Type="Italic">Cannabis sativa</Emphasis> L. (III): variation in cannabichromene proportion

The mechanism that controls the proportion of cannabichromene (CBC), a potential pharmaceutical, in the cannabinoid fraction of Cannabis sativa L. is explored. As with tetrahydrocannabinol (THC) and cannabidiol (CBD), CBC is an enzymatic conversion product of the precursor cannabigerol (CBG). CBC is reported to dominate the cannabinoid fraction of juveniles and to decline with maturation. This ontogeny was confirmed in inbred lines with different mature chemotypes. A consistent CBC presence was found in early leaves from a diverse clone collection, suggesting that CBC synthase is encoded by a fixed locus. Morphological variants possessing a ‘prolonged juvenile chemotype’ (PJC), a substantial proportion of CBC persisting up to maturity, are presented. PJC is associated with a reduced presence of floral bracts, bracteoles, and capitate-stalked trichomes. Genetic factors causing these features were independent of the allelic chemotype locus B that was previously postulated and regulates THC and CBD synthesis and CBG accumulation. In contrast to previously described Cannabis chemotypes, the cannabinoid composition of PJCs showed plasticity in that reduced light levels increased the CBC proportion. The ability of PJC plants to enable the production of pharmaceutical raw material with high CBC purity is demonstrated.     

Effects of plastic film mulch and tillage on maize productivity and soil parameters

This paper determined the effects of mulching time for double furrows and ridges using plastic film on soil water status, grain yield of maize, soil quality, and economic benefits. The study was conducted in a typical semiarid area during two growing seasons of 2006–2007 with the following three treatments: (i) plastic film mulching at maize sowing with conventional tillage, and the film was removed at harvest (CK); (ii) mulching applied 30 d before sowing with conventional tillage, and the film was removed at harvest (T1); and (iii) mulching at sowing with no-tillage, and the film left on the field after harvest in the first season and used for mulching in the second season (T2). The T1 in both years and T2 in the second year (2007) improved soil water content (in the 0–60 cm layer) and temperature (10 cm) at sowing compared with CK. After the two seasons, the soil water content was significantly higher in the 0–80 cm soil layer in CK and T1, and in the 0–120 cm soil layer in T2; however, it decreased significantly in 140–200 cm soil layer in CK and T1, compared to their initial values at sowing in April 2006, and there was no significant change in T2. The rainfall storage in the 0–200 cm soil layer during the non-growing season (late September 2006 to late April 2007) was 18.2 mm in CK, 34.0 mm in T1, and 59.7 mm in T2, and the rainfall storage in 100–200 cm soil layer was 16.5 and 18.6 mm higher in T2 than in CK and T1, respectively. In 2006, there were no significant differences in yield and water use efficiency (WUE) in all treatments. In 2007, the yield in T1 was significantly higher than in T2, but yields in T2 and CK were not significantly different, and there was no significant difference in WUE among treatments. Soil organic carbon (SOC) (0–20 cm) decreased in CK and T1, but increased (by 2.7%) in T2 at harvesting in September 2007 from the initial value of sowing in April 2006. The ratio of output to input was 1.32:1 for CK, 1.40:1 for T1, and 1.67:1 for T2 averaged across the two seasons. Therefore, T2 was a more sustainable model for increasing water storage, producing greater economic benefit and maintaining SOC balance for maize production in semiarid area.     

Water quality in drip/trickle irrigation: A review

Summary The intensive treatment of irrigation water required for the proper operation of drip irrigation systems is presently an accepted practice. To control emitter clogging, we need to know the basic causes of clogging. The major clogging factors have been identified and control measures developed to prevent emitter malfunction. All emitter clogging problems, however, have not been solved primarily because of cost. The main approach to control clogging is proper water treatment. The type of treatment is based on the quality of the irrigation water, which can be classified in terms of its physical, chemical and biological composition. The causes of emitter clogging and possible water treatment and preventive measures to maintain reliable operation are reviewed.     

Discrimination of ‘San Marzano’ accessions: A comparison of minisatellite, CAPS and SSR markers in relation to morphological traits

‘San Marzano’ (SM) is one of the most widely known tomato (Solanum lycopersicum L.) cultivars, and is a classic example of a local variety with a premium value. Unfortunately, the original cultivated form is underrepresented in the Protected Denomination of Origin (PDO) area because of the incidence of contaminant and phenotypically similar genotypes. Our aim was to examine the ability of three DNA marker systems (minisatellite, cleaved amplified polymorphic sequence (CAPS) and simple sequence repeat (SSR)) to reveal the genetic diversity of tomato accessions that were, based on a morphological analysis, very similar. The data indicate that both minisatellites and SSRs can be used to genetically distinguish the analysed materials. Furthermore, these two marker systems depict relationships consistent with the hierarchal pattern obtained by the morphological data. As locally cultivated tomato accessions are often characterised by some degree of genetic variability, our results will be valuable in facilitating the purification, management and breeding of tomato germplasms. The differences between the marker systems employed are also discussed in relation to their usefulness in the agro-food chain.     

Analysis of flowering,stigmas yield and qualitative traits of saffron (Crocus sativus L.) as affected by environmental conditions

Saffron is well known for its use as a condiment spice, as a dye and traditional medicine. Saffron is experiencing an increasing interest mainly due to its peculiar and manifold properties of the metabolic pool of its stigmas, mainly crocetin esters and picrocrocin. This species is cultivated in environments with very different climatic conditions and with very different corm rates from place to place, passed down over the centuries. The aim of this study was therefore the evaluation of the influence of rainfall, temperature and corm density on flower phenology, stigmas yield and main compositional characteristics of two saffron corms provenience. Flowering beginning in saffron seems to be influenced by the combination of temperature and soil moisture, whilst its flowering calendar proves independent of corm provenance, environment and plant density. On the contrary, the studied factors exert a strong effect on both total stigmas yield and qualitative characteristics: colder environment resulted in a higher flower production, but lower quality of stigmas. Flower number was positively correlated with the stigmas yield, but negatively with its unitary weight. The content of crocetin esters and picrocrocin has been evaluated according to the spectrophotometric ISO normative, which ranked the samples into three qualitative decreasing categories (I–III). The spectrophotometric data showed positive correlation with the unitary stigmas weight and negative with stigmas production.     

Correlation between chromaticity values and major anthocyanins in seven Acer palmatum Thunb. cultivars

The correlation between the anthocyanin concentrations of seven Acer palmatum Thunb. cultivars and the chromaticity values a*, b*, a*/b* ratio, h° and L* was investigated. According to the position of leaves on the branch terminal, middle and base sample leaves were analyzed and the positional effect on the level of the major anthocyanin was estimated. Leaf color was measured with a portable colorimeter and individual anthocyanins were detected with the use of HPLC–MS. Cyanidin-3-glucoside was present in all senescing leaves of Acer cultivars and its content decreased from terminal to base position. Cyanidin-3-rutinoside was identified in lower concentrations in the leaves of all cultivars. Multiple variable analysis was calculated for each of the tristimulus values and two major anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside) in senescing leaves of ornamental Acer cultivars. Correlations were detected between the major anthocyanin (cyanidin-3-glucoside) in analyzed Acer cultivars and all chromaticity parameters. The highest correlation coefficient (0.94) was observed between cyanidin-3-glucoside and a*/b* ratio in cultivar ‘Bloodgood’ and lowest (0.54) between cyanidin-3-glucoside and a* in Acer palmatum Thunb. The correlation between cyanidin-3-rutinoside and chromaticity parameters was not detected in all Acer cultivars, additionally correlation coefficients and statistical significance were much lower. The expression of red color in both senescing leaves and in all-year-red cultivars can be tightly linked with the content level of cyanidin-3-glucoside; the second major anthocyanin does not contribute much to the red leaf color.     

Identifying the location of olive fruit abscission

For high quality oil, table olive characteristics, and reduction of alternate bearing tendencies, it is often desirable to harvest olive fruits prior to full physiological maturity, that is, before the natural separation zone has differentiated. Olive fruit abscission can occur at different positions, mainly fruit-pedicel, pedicel rachis and peduncle-branch, apparently varying according to cultivar, fruit weight, and fruit maturation. Precisely identifying the location of separation is critical for studying the differentiation of the abscission zone or zones and testing the effectiveness of harvest procedures, including the mode of action of different fruit-loosening chemicals. We determined the olive fruit abscission zone position under natural conditions, throughout the complete fruit maturation period, for two cultivars differing in fruit size. The major separation zone for the cultivars studied was between the fruit and pedicel. For cv. Picual, abscission in zones other that fruit-pedicel occurred in less than 15% of the fruit at all dates throughout the maturation period, whereas in cv. Hojiblanca, the percentages of fruits detached at peduncle-shoot (27%) and pedicel-rachis (19%) were initially substantial, and then decreased progressively during fruit maturation. Our data clearly indicate both varietal and temporal differences which should be taken into account not only when testing fruit-loosening compounds but in extrapolating test results to different varieties or dates. Fruit weight did not appear affect the abscission location. The method we used, of counting the different detached units, is simple and effective for determining the position of fruit abscission.     

Regeneration of adventitious shoots from mature stored cotyledons of Japanese plum (Prunus salicina Lind1)

Adventitious shoot regeneration from mature stored cotyledons of Japanese plum (Prunus salicina Lind1) was achieved in vitro. The influences of the presence and absence of the light, different concentrations of thidiazuron (TDZ) and benzyladenine (BA) in the culture media, TDZ pretreatments and different basal salts on shoot regeneration were evaluated. TDZ was more effective in inducing shoot regeneration from mature stored cotyledons than BA. Dark incubation significantly increased the regeneration frequencies. Quoirin/Lepoivre (QL) basal salts stimulated shoot regeneration more than woody plant (WPM) or B5 salts did. The frequency of adventitious shoot formation varied among the varieties and the regeneration ability appeared to be genotype depended. The frequency of regeneration under the optimum tested conditions for ‘Bruce’, ‘Shiro’, ‘Redheart’, ‘Gladstone’ and ‘Early Golden’ cotyledons were 66.7%, 46.7%, 43.3%, 26.7% and 6.7%, respectively.