Cyanogenic glycoside content of Manihot esculenta subsp. flabellifolia in south-central Rondônia,Brazil, in the center of domestication of M. esculenta subsp. esculenta

Manioc (Manihot esculenta Crantz subsp. esculenta) is a tropical staple crop that was domesticated from M. esculenta Crantz subsp. flabellifolia in southwestern Amazonia. After domestication, different selective pressures created two large groups of varieties based on cyanogenic glycoside (HCN) content: sweet and bitter manioc. The characterization of HCN content in subsp. flabellifolia will help understand the original selection pressures that either reduced or increased the concentration of HCN in the edible root. We collected leaves, fruits and roots of five mature plants of subsp. flabellifolia chosen at random from each of six populations located in central Rondônia, Brazil. Analyses of HCN were performed by the enzymatic method with some modifications. All parts of the plant contained moderate to high (84–717 mg HCN kg^?1 fresh weight) concentrations of HCN, especially in the fruits. Both the bark and the starchy flesh of roots had moderate to high concentrations of HCN (198 ± 103 and 244 ± 105 mg HCN kg^?1 fresh weight, respectively), which classifies these populations as bitter.     

On the 80th birthday of V.A. Kuz’min

Jubilees

On the 80th birthday of V.A. Kuz’min     

Performance of a non‐nuclear resonant frequency capacitance probe. II. Measurement of dryland crop water use

Abstract

Resonant frequency capacitance techniques have been recently developed as a safe and reliable method for measuring water content of various materials. A previous study with a commercial capacitance probe (Troxler Sentry 200‐AP) showed it to be a safe, reliable, and a rapid method of in situ measurement of soil water content in the field provided it is calibrated for individual soils. Further testing of this resonant frequency capacitance probe was done to evaluate the performance of the probe by comparing results of field measured crop water use to those reported in similar studies using other methods of determining in situ soil water content in the field. These tests were done in two field experiments which were conducted during the summer of 1994 using corn and sorghum as the indicator crops. The experimental field was the same used to calibrate the capacitance probe in the previous study. Treatments consisted of three plant populations of corn and four plant populations in two cultivars of grain sorghum. The crop water use for corn and sorghum averaged over all treatments were 452 and 424 mm, respectively. The measured crop water use values for corn and sorghum were comparable to the crop water use values reported in several similar previous studies using different in situ soil water measuring instruments.     

Influence of root zone restriction on morihogenetic responses of spreading euonymus (E. Kiautschovica loes. ‘Sieboldiana')

Euonymus kiautschovica Loes. ‘Sieboldiana’ plants were grown in small‐volume (450 cm³) or large‐volume (13,500 cm³) plastic containers in the greenhouse in a medium containing sandy loam, perlite, and compost and harvested at 4‐week intervals from the time of planting until 20 weeks. Plants were irrigated with a nutrient solution 3x ‐ 5x daily to prevent water and nutrient stress. After 8 weeks, leaf number, leaf area, and shoot length of lateral shoots from plants grown in small‐volume containers were significantly less than those of plants grown in large‐volume containers for both lateral shoots and the total plant. These differences persisted for the next 12 weeks. There were no differences, however, in shoot length, leaf number, or leaf area of the main shoot of plants grown in large or small‐volume containers, even after 20 weeks of root restriction. Thus, the reduction in overall growth of root‐restricted plants could be attributed almost entirely to a reduction in growth of the lateral buds. These findings have important implications for researchers and growers involved in container culture, where root confinement frequently occurs.     

Origin and cytology of a novel cytotype of Allium tuberosum Rottl. ex Spreng. (2n = 48)

Naturally occurring/spontaneously produced polyploids with six/more genomes are rarely found in Alliums. A hexaploid form of Allium tuberosum with 2n = 48 chromosomes has been isolated for the first time amongst the open-pollinated seedlings of a hypotetraploid plant (2n = 4x = 31); latter being the seed-derived product of a normal tetraploid stock (2n = 4x = 32) growing in Jammu University Botanical Garden. Except for the guard cells and pollen grains that are of increased size, this form compared to its progenitor is dwarf, has smaller leaves and bears inflorescences with few flowers. This plant is also different from its progenitor in having nearly one-fourth (27.8 %) of its pollen mother cells (PMCs) with varying chromosome number viz. 27–64, with the remaining cells having somatic or double the somatic number of chromosomes. To assess the nature of hexaploid form, its chromosomes were studied for morphological details, putative grouping and pairing properties during reduction division. Morphological similarity in the chromosomes of the present cytotype and its progenitor, arrangement of 48 chromosomes in eight groups of six chromosomes each and presence of 21.88 % euploid cells with eight hexavalents pointed towards the autopolyploid nature of the present strain. Regarding the origin of this strain, observation made on the meiosis in the two sex mother cells of the progenitor provides some clues. In the later plant, presence of most of embryo-sac mother cells with 62 chromosomes that showed 31:31 segregations and existence of majority of the PMCs with 31 chromosomes exhibiting erratic segregations indicate that the hexaploid strain has probably originated as a result of the fusion of reduced male (n = 17) and unreduced female gamete (2n = 31).     

AGRICULTURAL METEOROLOGY A Comprehensive Table of Main Contents of 1996(Vol.17)

1.CropmeteorologyModelanalysisofclimaticconditionsandiceamountforthesafetransportationofvegetablesfromChengdutoNorthwestChina………………ChenGangyietal.(1.6)………………………Effectofwaterstressongrowth,developmentandecologicalfeaturesofdifferentanti-aridtypyofpeanutsLiJunqingetal.(1.11)…………………ErroranalysisofPenmant-Monteithequationun-dertheconditionsofunvalidityofflux-gradientre-lationshipsDengHuiping(1.14)…………………Meteorologicalfactorsandyieldincreaseeffectofoptimumcondition…     

Forms of Rare Earth Elements in Soils: Ⅱ. Differentiation of Rare Earth Elements

The present paper deals mainly with the relationships between the distribution of rare earth elements (REE) in different forms in soils and the atomic number and with the odd-even phenomenon in the distribution of ionic lanthanides in soils.The enrichment tendency of light REE relative to heavy REE in soils was pointed out on the experimental results about the proportions of Ce-group and Y-group elements in different REE forms in soils.Meanwhile,the differentiation of Tm in different soil REE forms was compared and the reasons why Tm is enriched in soils were preliminarily discussed.     

Substances in Urban Snow. A comparison of the contamination of snow in different parts of the city of Luleå, Sweden

The aim of the study was to investigate how the quality of snow varies within a city. The study area is situated in the Luleå municipality, in northern Sweden (lat. 65°35′N and long. 22°10′E). For this study, the city was divided into three different types of areas: housing areas, city centre and outskirts. In one area of each type, sampling sites were selected. Snow samples were taken at nine occasions, once every fourteenth day in the city centre and in the housing area. Analyses were carried out for pH, conductivity, suspended solids and both the total and dissolved concentration of phosphorus and selected metals. It was concluded that traffic or activities related to traffic were a major source of heavy metals and phosphorus in urban snow, both in the city centre and in the housing area. Also, the type of area and the design of the street were important for the quality of snow. A clear relation was found between the pH and the quantity of suspended solids in the snow. Higher pH values were found in snow samples from sites with higher traffic loads, and lower pH values at sites, which were the no-traffic sites, with small quantities of particles. The particulate and dissolved substances in the snow behaved in different ways.     

Identification of the tetrad-sterility-causing Solanum stoloniferum Schltdl. & Bouché cytoplasm in interspecific hybrids with S. tuberosum L.

Tetrad sterility, in which only clumps of four premature pollen grains are released from anthers, has been observed in some modern potato cultivars. It is a form of cytoplasmic male sterility caused by the cytoplasm derived from the Mexican tetraploid species Solanum stoloniferum Schltdl. & Bouché., an important source of resistance to Potato virus Y in potato breeding. However, since S. stoloniferum is highly polymorphic, the source of tetrad-sterility-causing cytoplasm is unknown among diverse S. stoloniferum accessions. In this study, we directly crossed 24 S. stoloniferum accessions with pollen from 4x?S. tuberosum and obtained 39 hybrids from 12 accessions. Nineteen hybrids from six accessions showed tetrad sterility, with either D/γ- or W/γ-type cytoplasm, and were triploid, tetraploid, or hexaploid. The W/γ-type cytoplasm was not necessarily associated with tetrad sterility. Sequence comparisons of 17 mitochondrial genes and their intergenic regions revealed a length polymorphism in the intergenic region between rpl5 and rps10, in which an amplified band of 859 bp was associated with tetrad sterility. This specific cytoplasm causing tetrad sterility is named TSC_sto. The 859-bp band will be a useful diagnostic marker for identifying TSC_sto in potato breeding.

     

Microsatellite mapping of genes for semi-dwarfism and branched spike in Triticum durum Desf. var. ramosoobscurum Jakubz. “Vetvistokoloskaya”

A combination of increased harvest index and increased seed number per plant may improve wheat yield. We found an accession Triticum durum Desf. var. ramosoobscurum Jakubz. “Vetvistokoloskaya” R-107, whose plant height was short and spike was branched. To characterize R-107, we mapped the genes for semi-dwarfism and branched spike. Semi-dwarf gene Rht_R107 (Reduced height R107) from R-107 was allelic to Rht11 and Rht-B1b on chromosome 4BS. Rht_R107, as well as Rht11, was recessive and insensitive to gibberellic acid. Microsatellite mapping indicated that Rht_R107 was linked to Xwmc48 (1.2?cM) on chromosome 4BS, and Rht11 was also linked to Xgwm495 marker (19.4?cM) on chromosome 4BS. The locus responsible for branched spike in R-107 was mapped by genotyping three F₂ populations using microsatellite markers. Phenotypic analysis revealed that branched spike was under control of a recessive allele at a single locus. The bh (branched head) locus was located on chromosome 2AS and the marker Xgwm425 flanked the bh gene proximally.     

Characterization of Vitis vinifera L. Cv. Carménère grape and wine proanthocyanidins

A formal compositional study of the proanthocyanidins of Vitis vinifera L. cv. Carménère was conducted in this work. We first characterized the polymeric proanthocyanidins of Carménère skins, seeds, and wines. In addition, the wine astringency was analyzed and compared with Cabernet Sauvignon. Although Carménère wines had a higher proanthocyanidin concentration and mean degree of polymerization than Cabernet Sauvignon wines, the former wines were perceived as less astringent. The low seed/skin proportion in Carménère wines as compared to other varieties, as evidenced by the reduced number of seeds per berry and the higher amount of epigallocatechin subunits of Carménère wine proanthocyanidins, could explain this apparent paradox.     

Performance of a non‐nuclear resonant frequency capacitance probe. I. Calibration and field testing

Abstract

Accurate and rapid methods for in situ measurement of soil water content of field soils are required for assessment of plant growth conditions, crop water balance, and irrigation scheduling. Advances in electronics have made possible the recent development of a commercially available non‐nuclear resonant frequency capacitance probe (Troxler Sentry 200‐AP) for measuring water content of various materials. However, the performance of this probe to measure soil water content of the field soils in situ has not been widely reported. This study was undertaken to identify the need for field calibration and to understand the calibration process and evaluate the performance of the capacitance probe. A field calibration curve for a Uchee loamy sand was made for the Sentry 200‐AP probe. In situ volumetric soil water content obtained using this calibration curve differed markedly from those obtained using the factory calibration provided with the probe. The capacitance probe was found to be more sensitive at the lower range (<40%) of soil volumetric water content. However it appears to be reliable and to give reproducible results.     

Seasonality of nutrients vis-à-vis fruit quality of pomegranate cv. Bhagwa on vertisol

The temporal changes of nutrient concentration in leaves and their accumulation in fruit are good indicators of plant nutrient demand for each developmental stage. Seasonality of nutrients in leaves and fruits of pomegranate and their relation with fruit quality was evaluated in commercial orchards using cv. “Bhagwa.” The concentration of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), iron (Fe), zinc (Zn) and boron (B) in leaves decreased while calcium (Ca), magnesium (Mg), manganese (Mn) and copper (Cu) concentration increased during fruit growth and development. Total nutrient accumulation increased gradually in fruit and translated into growth of arils, and increase in juice content and total soluble solids, however as the biomass accumulation in fruit was much faster than nutrient accumulation, concentration of majority nutrients except Mg decreased rapidly, followed by slow and continuous decrease till maturity. During fruit enlargement, demand for N, P, K, Fe, Cu and Zn was high while requirement for Ca, Mg and S was high during fruit development.     

AGRICULTURAL METEOROLOGY A Comprehensive Table of Main Contents of 2002(Vol.23)

Ｎｏ .1ＩｎｆｌｕｅｎｃｅｏｆｔｅｍｐｅｒａｔｕｒｅａｎｄｃｏｎｃｅｎｔｒａｔｉｏｎｏｆＣＯ2 ｏｎｃｒｏｐｒｅｓｐｉｒａｔｉｏｎ ＬＩＵＪｉａｎ ｄｏｎｇｅｔａｌ.(1)……………Ｃｏｒｒｅｌａｔｉｏｎａｎａｌｙｓｉｓｏｆｔｅｍｐｅｒａｔｕｒｅａｎｄａｇｒｏｎｏｍｉｃｃｈａｒ ａｃｔｅｒｓｏｆｒａｔｏｏｎｉｎｇｒｉｃｅ ＲＥＮＴｉａｎ ｊｕｅｔａｌ.(4)………Ａｓｔｕｄｙｏｎｔｈｅｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｔｈｅｉｎｄｅｘｏｆｓｐｒｉｎｇｄｒｏｕｇｈｔａｎｄｗｉｎｔｅｒｗｈｅａｔｏｕｔｐｕｔｉｎ…     

Mechanism of manganese toxictty and tolerance of plants VII. effect of light intensity on manganese‐induced chlorosis

Effect of light intensity on Mn‐induced chlorosiss was investigated with bush bean (Phaseolus vulgaris L.) and corn (Zea mays L.) seedlings. The seedlings were grown in nutrient solutions containing different concentrations of Mn in enclosures which transmitted different percentages of the total solar radiation. At high levels of Mn in nutrient solution, the increase in light intensity increased the Mn uptake by the plant and resulted in a decrease in the chlorophyll content of the leaves. Even at similar levels of Mn concentrations within the leaves, high light intensity increased the severity of Mn‐induced chlorosis.

Photobleaching experiments were carried out with isolated chloroplasts suspended in media containing 0, 10^‐4 , 10^‐3,10^‐2 and 10^‐1 M Mn²⁺. Addition of Mn²⁺ to the medium decreased the extent of photobleacing of chlorophyll with increaing Mn²⁺ concentration up to 10^‐3 M . In concentrations of Mn²⁺ higher than 10^‐3 M, the extent of bleaching was increased again, accompanied by precipitation of oxidized manganese in the medium.

It is suggested that high light intensity stimulates not only the Mn uptake by the plant but also the destruction of chlorophyll when Mn in excess.     

Prof. Dr. Habil. Dr. H. C. Martin Körschens Zum 65. Geburtstag

Minimierung von Stoffbelastungen und Sicherung der Nachhaltigkeit sind die beiden Seiten, die Kriterienauswahl und Bewertungsprozeß der Kategorie Düngung prägen.

Das Gefährdungspotential der Kategorie wird durch 13 quantifizierbare und kontrollfähige Kriterien beschrieben. Für diese werden ökologische Optima und kritische Belastungen definiert, die die Grundlage für Bewertungsprozesse von Landwirtschaftsbetrieben bilden. Gleichzeitig wird damit ein Rahmen vorgegeben, der standortbezogen den tolerierbaren und damit umweltverträglichen Bereich der Düngung absteckt. Mittels dieses Rahmens können Betriebe umfassend bewertet, Problemfelder identifiziert und Korrekturerfordernisse formuliert werden.     

Interaction of NPK fertilizers during their transformation in soils: Ⅲ. Transformations of monocalcium phosphate

Interactions of N, P and K fertilizers in soil-plant systems are widely recognized. This study focused on the transformations of monocalcium phosphate (Ca(H2PO4)2) (MCP) with co-application of ammonium and potassium fertilizers in three different soils. The results showed that after 1 d incubation a large portion of the MCP applied in the paddy,calcareous and red soils became the water-insoluble form and the recoveries of P applied as Olsen P varied greatly in these three soils. Application of ammonium sulfate ((NH4)2SO4) (AS) or potassium chloride (KC1) reduced WSP significantly in the soils with AS more effective than KC1 in the calcareous soil, while the reverse occurred in the red soil. Meanwhile, in the paddy soil, co-application of the two fertilizers reduced WSP more than when the fertilizers were applied individually. The co-application of AS with MCP in the paddy and calcareous soils significantly reduced Olsen P, but the opposite occurred in the red soil. The experiment on the effect of different accompanying anions showed that the ammonium fertilizers (PNC1 and PNS) reduced WSP more effectively than the corresponding potassium fertilizers (PKC1 and PKS) in the calcareous soil due to the difference of the cations, whereas in the red soil, the chlorides reduced WSP more effectively than the sulfates. Overall, co-application of ammonium or potassium fertilizers with MCP significantly decreased availability of P from MCP during its transformation in soils, especially when MCP was applied in combination with ammonium in the calcareous soil.     

Forms of Rare Earth Elements in Soils: Ⅰ. Distribution

The distribution of rare earth element (REE) forms in soils is given in the present paper on the basis of sequential fractionation and determination of 34 representative surface soils collected from all parts of China.Results obtained show that the extraction rate of water soluble and exchangeable REE had the odd-even phenomenon and that of organically bound REE from La to Lu tended to reduce gradually with the increase of atomic number.The stability of Sc and the activity and enrichment of Tm in soils are proposed.Furthermore,the paper makes a preliminary discussion on the differences in the concentration distribution of various forms of individual REE in some soils.