印度Leh地区沙棘叶中脂肪酸的含量

本文用气相色谱仪分析了印度Leh地区沙棘叶油中种脂肪酸的含量,结果显示：该地区沙棘叶油中富含硬脂酸,其值可以达到13．853％,山嵛酸13．938％,亚油酸7．579％,掬焦油酸6．638％,十八稀酸4．622％。     

沙棘叶子提取物对白化病白鼠由铬诱导氧化胁迫的抗氧化活性评估

本研究报道沙棘(胡颓子科)对雄性白化病白鼠由铬诱导氧化胁迫的抗氧化活性。氧化胁迫通过对小白鼠进行强制性喂养30 d,以浓度为30 m g/kg的铬相对体重比例的重铬酸钾盐实现。铬促使体重下降,而却明显增加了器官与体重比例。铬处理明显减少了谷胱甘肽的降低,增加了丙二醛和肌氨酸磷酸激酶的水平;而且它还加强了血清中谷氨酸草酰乙酸转移酶和谷氨酸丙酮酸转移酶的浓度。用不同剂量的沙棘叶子提取物(乙醇提取)对保护铬元素诱导的氧化胁迫进行了评估,结果表明叶子提取物在浓度为100到250 m g/kg铬与体重比的情况下可以明显保护动物避免由铬所诱导的氧化伤害。     

The Influence of Plant Developmental Stage on Expression of Resistance to leaf Rust (Puccinia recondita) in Two Near Isogenic Lines of Wheat

Cultivar ‘Thatcher’, and ‘Thatcher’ lines with Lr 21 and Lr 22 were studied against a number of races of Puccinia recondita for seedling and adult plant reaction. The study has established that Lr 21 and Lr 22 are genes effective against P. recondita at adult plant stage. It has also shown that these genes confer resistance against all races when plants are inoculated at boot leaf stage.     

An analysis of genes for resistance against Indian stem rust races in two bread wheat cultivars

Summary The genetic constitution of two bread wheat accessions from the International Spring Wheat Rust Nurseries (E 5883 and E 6032) has been studied for reaction to four Indian races of stem rust. Analysis of E 5883 has revealed that for each of the races 15C, 21 and 40 a single dominant gene operates for resistance. The dominant gene against race 15C was identified as Sr6. The dominant genes for resistance against races 21 and 40 were found to be different from the genes described so far. Resistance against race 122 is controlled by a single recessive gene producing characteristically a 2 type of reaction. This gene was identified as Sr8.The resistance of E 6032 against each of the races 15C, 21 and 40 is controlled by two genes, one dominant and one recessive, which act independently. Dominant genes effective against 15C, 21 and 40 were conclusively identified as Sr6, Sr5 and Sr9b, respectively. From the correlated behaviour against races 15C and 40 as well as from the phenotypes of the resistance reactions rhe same recessive gene, undescribed so far, operates against the two races. The second recessive gene operating against race 21 was also observed to be different from those so far designated. E 6032 was, however, found to be susceptible to races 122.The presence of Sr6 both in E 5883 and E 6032 against race 15C was further confirmed through F₂ and F₃ segregation data.     

Novel complementary genes for adult plant leaf rust resistance in a wheat stock carrying the 1BL-1RS translocation

The wheat-rye translocation (IBL-IRS) that carries the tightly linked genes Lr26/Sr31/Yr9, has been widely exploited in the development of wheat cultivars worldwide. This resistance, however, has become ineffective owing to the evolution of new pathotypes of Puccinia recondita that neutralize the resistance of Lr26. Inheritance studies on ‘Federation4′/‘Kavkaz’ revealed complementary genes derived separately from ‘Federation’ and ‘Kavkaz’ for adult plant resistance. This previously undescribed source of resistance appears to be widely effective and could therefore be used to broaden the genetic base for resistance in India. Its effectiveness in other geographical areas is unknown.     

Micronutrient Distribution in Different Physiographic Units of the Siwalik Hills of the Semiarid Tract of Punjab,India

We investigated the profile distribution of total and diethylenetriamine pentaacetic acid ( DTPA )- extractable micronutrients ( Zn , Mn , Cu , Fe ) in soils developed on six physiographic units of the semiarid Siwalik hills of Punjab in northwest India . The soils showed a gradual fining of texture from shoulder slopes to toe slopes . All soils were alkaline and calcareous . In general , total and DTPA-extractable micro nutrients were higher in surface horizons and decreased in subsurface horizons . However , none of the micronutrients exhibited any consistent pattern of distribution with depth on different geomorphic surfaces . Physiography had a strong influence on the spatial distribution of total and available micronutrients . Contents of all micronutrients and their forms were higher in fine-textured and uneroded soils than in coarse-textured eroded soils . Soil pH , calcium carbonate , organic matter , and size fractions had strong influence on the distribution of total and extractable micronutrients . Based on linear coefficients of correlation , total content of micro nutrients increased with increase in clay content , whereas DTPA - extractable micronutrient content increased with increase in organic carbon and decreased with increase in pH and CaCO3 content . Except for Cu , no other micronutrient showed influence of total reserves on availability of the respective micronutrient . Among the various micronutrients , deficiency of Zn was found to be widespread , followed by Fe and Cu in the cultivated soils on foot slopes , toe slopes , and floodplains .     

Photoperiod-sensitive male-sterile mutant in tomato and its potential use in hybrid seed production

Summary

The current practice of manual emasculation of tomato ¯owers for hybrid seed production is labour-intensive and contributes signi®cantly to the high cost of seed. Here we report on a photoperiod-sensitive, single gene male-sterile mutant (7B-1) in tomato which is 100% male sterile in long days (LD, minimum of 12.h daylength) in summer ®eld conditions, but produces many male-fertile ¯owers in short days (SD, 8.h). In LD, 7B-1 ¯owers contain stamens that are pale, short and in the anthers microspore mother cells are differentiated but meiosis does not occur, i.e. microspores and pollen grains are not formed. Unlike the wild type ¯owers, the style and stigma of 7B-1 ¯owers are well exposed and this allows for ready access for pollination without emasculation. In SD, mutant ¯owers possess normal-looking orange-yellow anthers that enclose the stigma and produce normal viable pollen, which when used for pollination of 7B-1 ¯owers yield good fruit- and seed-set. The 7B-1 seed in turn generate a 100% population of male-sterile plants all of which can be used as female parents for hybrid seed production. The female fertility is not affected in 7B-1 ¯owers in both LD and SD conditions. The 7B-1 mutant has been grown in various ®eld locations including, Saskatoon, California, Florida and in Chile, and at all locations it has shown stable male sterility. The 7B-1 mutant is a simple, natural and costeffective system that has a strong potential for use in commercial-scale production of tomato hybrid seed.     

Temperature effects on male fertility and flower and fruit development in Capsicum annuum L.

Temperature conditions strongly influenced the development of flowers and fruits of pepper (Capsicum annuum L.) plants. Low temperatures (LTR; 18°C day/15°C night) had much more effect on flowers and fruits than intermediate (ITR; 23°C day/18°C night) or high (HTR; 28°C day/23°C night) temperatures. LTR caused the formation of abnormal petals, stamens and gynoecium in the flowers. Stamens produced were deformed, in some cases partly carpel-like, produced abnormal non-viable pollen, and were thus functionally male-sterile. In the gynoecium, the ovary size of LTR-grown flowers was larger than that of ITR and HTR flowers, but the style elongation was inhibited. Fruits produced under HTR were larger than ITR and were seeded under both temperature regimes. Under LTR, small seedless fruits were produced, but normal seeded fruits were formed if flowers were pollinated with pollen from ITR- or HTR-grown flowers.     

Leachability of Arsenic from Field Containers Filled With Plant Growth Medium Amended With Biosolids Compost

The leaching of arsenic (As) from plant growth medium, admixed with different proportions of composted biosolids in field containers, was determined over a four-month period. Eight-week-old perennial flowers, Coreopsis grandiflora L, were transplanted in the field in 2-L containers filled with plant growth media. The treatments were replicated three times and rainfall was supplemented to supply 2 cm of water per day. Water percolating through potted plant containers was collected biweekly and analyzed for As using graphite furnace atomic spectrometry. The concentrations of As in the leachates increased with increasing proportions of compost in the medium and decreased with time of leaching, generally remaining below the drinking water standard of 50 μg/L after two months. Leaching of As occurred at a rapid rate initially but then continued at a slow rate. Compared to other metals of concern, as Cd, Cr, Ni and Pb, As in the compost appeared more mobile.