冬大麦茎秆生长的化学控制

在杭州进行的以二棱皮大麦浙农大3号(Hordeum distichum L. var. Z. A. U no.3)和四棱皮大麦威24(H. vulgare L. var V24)为材料的田间试验结果显示,选用的5种植物生长调节剂(组合)中,GR90—2、GR90—4和GR90—5在孕穗期一次性叶面喷播可有效地降低收获期的植株高度,且除GR90—5处理的行粒产量显著低于对照外,其它处理的籽粒产量与对照均无显著差异。对主茎各节间长度的分析表明:除GR90—1外,生长调节剂处理均使植株的穗下节和倒二节节间显著缩短,其中处理GR90—5还显著缩短了基部第二节间的长度。鉴此,作者认为,通过调整喷播时期和剂量,可望获得能有效控制冬大麦节间长度、增强植株抗倒伏能力,在正常生长条件下对产量无不良影响的生长调节剂配方。     

Cell selection as a possible reason for the specificity of somaclonal variation in pea

A study of regenerants obtained from long-term callus cultures of different pea (Pisum sativum L.) genotypes revealed specificity of in vitro mutagenesis. The specificity was displayed in the preferential generation of the somaclonal variations affecting quantitative and developmental characters. About 60% of regenerated lines obtained from the cultivar Ranny Zeleny carried mutations in the Lf and Sn loci, which control initiation of flowering. An in vitro study of isogenic lines differing at the Lf and Sn loci illustrates the growth advantages of mutant genotypes in tissue culture. These experiments suggest that mutations affecting developmental characters (e.g. mutations in loci which control flowering behaviour) may be expressed in tissue culture and may cause increased adaptation in mutant cells to the in vitro conditions. Rapid propagation of mutant cells during in vitro culture may lead to a higher proportion of quantitative mutations among the regenerated plants.     

Spring Cereals for Forage and Grain Production in a Cool Maritime Climate

Newfoundland's climate is marginal for agricultural production. The availability of locally grown cereal grain and high‐quality forage are major limitations to successful animal agriculture in this region. Here, our overall objective was to compare several spring cereal species for both annual forage and grain production in Newfoundland's cool Maritime climate. Several varieties of barley (Hordeum vulgare L.), wheat (Triticum aesitivum L.), oats (Avena sativa L.) and pea (Pisum sativum L.)–cereal mixtures for forage yield and quality, as well as grain yield and maturity, were compared in field trials on the east and west coasts in both 1999 and 2000. Barley headed earliest, yielded greatest forage dry matter, had lowest forage protein and acid detergent fibre (ADF) percentages, and had neutral detergent fibre (NDF) mean values greater than those of pea–cereal mixtures, but less than those of oats and wheat. Forage harvested from pea–cereal mixtures was similar to that of barley for yield, ADF and NDF, while P and protein percentage were much greater. Barley matured 10–15 days earlier than both wheat and oats. In general terms, all three spring cereals exhibited similar grain yield potential. Oats tillered less, but compensated by producing more kernels spike^?1. Days to maturity for cereal grains in western Newfoundland were roughly similar to those reported for the Maritime provinces of Canada. Yield and maturity results for both forage and grain production suggest that eastern Newfoundland is a unique agro‐ecoregion in North America, and agronomic recommendations specific to other regions may not be applicable in this region.     

Genetic Engineering in Pea Crop Improvement

Abstract

Genetic engineering can be used to complement traditional breeding programmes in those plant species where suitable tissue culture and transformation methods allowing regeneration of fertile transgenic plants have been developed. Pea, an important legume crop, was earlier considered to be recalcitrant to genetic engineering. Recent advances in tissue culture methods have, however, made it possible to obtain fertile transgenic pea plants. This paper summarizes the results obtained in developing transformation methods for pea.     

Characterization of pea accessions by SRAP's markers

Sequence-related amplified polymorphism (SRAP) and morphological markers to estimate the genetic relations among forty pea varieties (Pisum sativum L.) were studied. Data on 15 morphological traits were collected and analyzed. A total of 162 polymorphic SRAP's bands were scored using seven combinations of primers. Cluster analysis and both principal component and principal coordinate analysis were carried out. The varieties were grouped in four clusters through procrustes generalized analysis. Relationships among varieties revealed by molecular markers were significantly correlated with those based on the agronomic traits, suggesting that the two systems give similar estimates of genetic relations among the varieties. Parents selection depend on the specific objectives in further breeding programs.     

酸性成纤维细胞生长因子的分离纯化及活性分析

以瞬时表达酸性成纤维细胞生长因子(aFGF)的豌豆(Pisum sativum L.)为试验材料,提取豌豆中可溶性总蛋白质,利用Western blot方法检测目的蛋白质,结果表明豌豆可成功表达aFGF;采用肝素亲和柱层析法分离目的蛋白aFGF,并用MTT法检测aFGF的生物学活性,结果表明豌豆中表达的酸性成纤维细胞生长因子具有促细胞分裂活性.     

植物激素配比对大蒜茎盘愈伤组织再生体系的影响

植物激素对大蒜茎盘愈伤组织再生的各个环节都发挥着重要的作用。试验结果表明：2,4．D对茎盘愈伤组织的诱导具有主要作用，高浓度的2，4-D有利于大蒜愈伤组织的诱导，但并不利于其增殖分化。MS＋NAA 2mg／L＋BA 1mg／L培养基适宜于愈伤组织的继代增殖，MS＋NAA 1mg／L＋BA 5mg／L培养基适宜不定芽的分化，只添加NAA或无激素的MS培养基有利于不定芽生根。     

Cultivar × rhizobial strain interactions in peas with respect to early symbiosis, nodule initiation and N uptake

Sixteen pea cultivars differing in their phenotypic characteristics were studied in order to characterize the cultivars' variability in symbiotic characters using three Rhizobium leguminosarum biovar viceae strains. The peas did not show any cultivar × strain interactions with the rhizobial strains used with respect to root hair infection frequency or day of nodule initiation. Three cultivars had high root hair infection frequencies, and five had only a few infected root hairs. Four of five leafless/semi-leafless varieties investigated and one cultivar with normal leaves formed nodules quickly, whereas three varieties with normal leaves formed nodules slowly. Ten of the cultivars showed cultivar × strain interactions with respect to N uptake, indicating that the performance of the N2-fixing symbioses depends on the rhizobial partner. Six cultivars showed cultivar × strain interactions with respect to dry matter production and the nodule proportion of the dry matter. Of the cultivars investigated, we conclude that some of the leafless/semi-leafless varieties (‘Capella’, ‘Filby’ and ‘Solara’) are suitable for inclusion in a future breeding programme, since these cultivars combined several important symbiotic characters.     

Expression of garlic leaf lectin under the control of the phloem-specific promoter Asus1 from Arabidopsis thaliana protects tobacco plants against the tobacco aphid (Myzus nicotianae)

BACKGROUND: To check for correlation between the insecticidal properties and the specificity of lectins, a comparative study was made of the insecticidal activities of two garlic lectins with different biological activities.RESULTS: The insecticidal activity of the garlic (Allium sativum L.) leaf lectin ASAL and bulb lectin ASAII towards the tobacco aphid Myzus nicotianae Blackman was studied using bioassays with transgenic tobacco (Nicotiana tabacum L. cv. Wisconsin 38). Bioassays were started with newborn nymphs of the tobacco aphid. Although during the first 7-8 days when nymphs developed to adults there were no apparent effects, part of the nymphal population was found to develop into winged (alate) forms. Later it became clear that transgenic plants expressing ASAL and ASAII had a significant effect on the reproduction capacity of the resulting adults, with a reduction of up to 40%. Different life table parameters such as prereproductive time, intrinsic rate of natural increase, generation time and doubling time were significantly affected (P < 0.05) in aphids grown on transgenic plant material expressing ASAL and ASAII.CONCLUSION: Bioassays with tobacco plants expressing ASAL and ASAII demonstrated a significant impact on the population growth of M. nicotianae. Therefore, both lectins can be considered as valuable candidate aphid control agents.     

Genetic,biochemical and pathogenic diversity of Pseudomonas syringae pv. pisi strains

Pseudomonas syringae pv. pisi is a seedborne pathogen distributed worldwide that causes pea bacterial blight. Previous characterization of this pathogen has been carried out with relatively small and/or geographically limited samples. Here, a collection of 91 strains are examined that include strains from recent outbreaks in Spain (53 strains) and from 14 other countries, and that represent all races and the new race 8, including the type race strains. This collection was characterized on the basis of 55 nutritional tests, genetic analysis (rep‐PCR, amplification of AN3 and AN7 specific markers, and multilocus sequence typing (MLST)) and pathogenicity on the differential pea cultivars to identify races. Principal component analysis and distance dendrograms confirm the existence of two genetic lineages within this pathovar, which are clearly discriminated by the AN3/AN7 markers, rep‐PCR and MLST. Strains from races 1 and 7 amplified the AN3 marker; those from races 2, 6 and 8 amplified AN7, while strains of races 3, 4 and 5 amplified either AN3 or AN7. Nevertheless, strains were not grouped by race type by any of the genetic or biochemical tests. Likewise, there was no significant association between metabolic and/or genetic profiling and the geographical origin of the strains. The Spanish collection diversity reflects the variability found in the worldwide collection, suggesting multiple introductions of the bacteria into Spain by contaminated seed lots.