It was very difficult to specifically identify the maintainability of a plant line unless it is genetically stable and its whole nuclear genome has completely replaced in the CMS (cytoplasmic male sterile) line. To overcome this problem, a breeding method was proposed in this paper. The breeding procedure includes: (1) screening elite male sterile plants from segregating populations using male sterile cytoplasm as background selection; 2) getting genetically stable CMS lines via anther culture or parthenogenesis; (3) selecting target CMS lines with good combinability, restorability, outcrossing habit, grain quality and resistance to pests and diseases; (4) converting target CMS lines into maintainers by the following approaches: (a) to obtain fertile mutants of target CMS lines by further anther culture; (b) to make the target CMS line fertile by high temperature treatment at young panicle stage, then to select maintainers through screening their offspring, or through nuclear substitution using their offspring as male recurrent parent; (c) to irradiate to the obtain hybrids between CMS cells and radiated normal cells via protoplast fusion and screen fertile plants as new maintainers.

Recent advances in the studies of phototropism are reviewed in this paper. Phototropin and cryptochrome are the two key photoreceptors of plant phototropism, and phytochrome plays an important role in plant phototropism too. The root of rice and Arabidopsis thaliana have the characteristic of negative phototropism, the curvature is the vector sum of the negative phototropism and gravitropism. Many new investigations have presented evidences that both asymmetric localization and dynamic redistribution of IAA carrier is consistent with the role of controlling the polar IAA transport.

Sugars play a central role in plant life. They not only are important energy sources and structural components but also act as central signaling molecules controlling gene expression, growth and development. This paper reviews different mechanisms of sugar sensing and signaling, and the relationship between sugar signal and hormone signal.

Endoreduplication is a special phenomenon of nuclear polyploidization that results from lacking of mitosis. When cell cycle repeats S-phase and can not enter M-phase, endoreduplication occurs. The caracter of endoreduplication is the inactivation of MPF and oscillatory activation of CDKs. Endoreduplication has been observed in many plant and animal species, and is documented to appear more frequently in tissues with high metabolic activity and highly differentiated cells. Therefore, it may play an important role in cell proliferation and cell enlargement. This paper has reviewed recent progress in the study of the molecular mechanism and regulators of endoreduplication in representative plants and mammals.

Seed development, which involves in multiple genes and their interactions, is a central part of the reproductive process in angiosperms. Recent studies have highlighted the differential expression between male and female genomes, the mechanism of epigenetic processes and the regulation network of development. Studies on genes related to embryo and endosperm development are leading us to an extensive understanding of the mechanisms of seed development and apomixis at the molecular level, which will benefits the research for yield and quality improvement of plant seeds via genetic engineering.

Effects of different low temperature stresses (14℃ and 4℃) on cyanide-resistant alternative pathway development and operation, as well as on alternative oxidase expression in plant calli of tobacco (Nicotiana rustica L.) were compared. The results showed that both alternative pathway capacity (Valt) and its actual operation activity (rValt) were dramatically induced under the two different low temperature stresses, and the change patterns of Valt and rValt were similar: both of them were induced at the early stage of stress treatment, the highest was found on 3 d and then declined to a relatively constant level. The increase of Valt was in relation to the temperature decreased, while no significant difference of rValt induced between 14℃ and 4℃. This suggests that responses of Valt and rValt to different temperature stress are different. The immunoblot results indicated that low temperature stress remarkably induced the content of total alternative oxidase (AOX) protein, and the changing mode throughout the stress was similar to Valt. The results of variation in AOX monomer and homodimer contents under stress treatment showed that AOX is largely located in mitochondria membrane of tobacco callus as the oxidized form (homodimer), and the existing state could not be changed by low temperature stress. The amount of monomer and homodimer both induced by low temperature stress, but no appreciable differences in the content of monomer was observed between two different low temperatures, and the level of homodimer induced under 4℃ was higher than that under 14℃. Our results suggest that, effects of low temperature on the development of cyanide-resistant alternative pathway are mainly due to the differently induced content of AOX homodimer under different low temperatures. The content of highly active AOX monomer form is not obviously induced by aggravating low temperature stress, thus the operation degree of cyanideresistant alternative pathway shows no notable difference between two kinds of low temperatures tested.

The protoplasts of Ipomoea batatas ‘koganesengan’ and Ipomoea batatas ‘bitambi’ were fused with PEG method. Forty-five plants were obtained from fusion-treated protoplasts. Four of the regenerated plants are considered to be somatic hybrids. They show various intermediate characters between the two parents. Among them, two have chromosome numbers that corresponds to the sum of their parents (2n=12 ×（2n+2n）=180), the other two have chromosomes varying from 45 to 103 and from 35 to 100, respectively, in cells. The hybridity is confirmed by RAPD markers.

Expansin is first identified as cell-wall-loosening protein. Its function is involved in regulating cell expansion and fruits softening. Because its typical characterization is the ability to induce the extension of isolated cell walls, extensometer is necessary for detection activity of the protein. A new sensitive and accurate extensometer with simple structure was installed using transducer as the key component. Characteristics of expansins from roots, stems, epicotyls and mature leaves of Vicia faba were studied using the extensometer. Results showed that there were expansins in all the tested organs and it was approved further by western-blot analysis. The activity of expansins from roots and leaves was higher than that from epicotyls and stems. The results suggested that our extensometer was sensitive enough to study expansins and the existence of expansin in mature leaves was reported firstly.

The aqueous two-phase partition method was used to isolate and purify plasma membrane (PM) vesicles from mung bean hypocotyls. The PM vesicles were purified well when the proportion of the weight of hypocotyls and two-phase partition reached 32:8. Bovine serum albumin in homogenization medium influenced the latency activity of the PM H+-ATPase. The enzyme hydrolysis activity was Mg2+ dependent and was strongly stimulated by Ca2+. Fusicoccin (FC), an activator of PM H+-ATPase, stimulated the enzyme activity with the maximal increase of 72% in vivo and of 30% in vitro as compared with control.

The study focuses on the influential factors of ISSR experiments used to analyze Korean pine. Comparative experiments on DNA extraction and PCR amplification among fresh leaves, dry leaves, embryos and endosperms were conducted. The results showed that the four kinds of materials were all feasible. The effect of purity and concentration of template, dNTP and TaqDNA polymerase on amplification was analyzed. Different annealing temperature, extension time and cycle times were also compared. 17 primers with stable amplification and rich polymorphism for ISSR were screened. The reaction condition of ISSR experiment of Korean pine was discussed, which was a basis for the study on genetic divergency among Korean pine populations.

In this work, the effects of culture factors ( MET, IBA, culture medium and culturing in dark) on root formation were studied in tissue culture of Celastrus angulatus. The results showed that the root induction was significantly affected by duration of culture in dark, while other factors were least effective. The order of their efficiencies was: duration of culture in dark＞culture medium ＞MET×IBA＞MET＞IBA.The best culture medium for root induction of Celastrus angulatus was that containing: 1/2 MS+MET3.0 mg.L-1+IBA 0.8 mg.L-1 or 1/2 MS+ MET3.0 mg.L-1 + IBA 0.5mg.L-1 for 12 days, in dark.

Embryo rescue of hybrid Chrysanthemum was studied in this paper. The results indicated that the genotype of Chrysanthemum, the developmental stage of embryo and hormone were critical for successful rescue of hybrid embryos. The closer the parental genotypes are, the better it is for embryo rescue. KT 2.0 mg.L-1+IAA 2.0 mg.L-1 in a medium promoted embryo germination, whereas BA 2.0 mg.L-1+NAA 2.0 mg.L-1 promoted the formation of calli and plantlets.

Stem-tips of pineapple (Ananas comosus (L.) Merr.) were cultured on a modified MS medium supplemented with various concentrations (1.0, 2.0, 3.0, 4.0, 5.0, 6.0 mg.L-1) of adenine (Ad). There were no significant effects on shoot culture and bud proliferation culture as compared with the contrast (Ad-free MS medium). However, bud growth rate on the stage of elongation culture was significantly higher than the control, under the Ad concentrations more than 1.0 mg.L-1 mg in the medium.The results also showed that the concentrations (3.0～5.0 mg.L-1) of Ad are the best for bud elongation. In these conditions, the period of elongation culture can be reduced 30 days at least.

The ABC model was established in late 1980s to explain the genetic interactions between floral homeotic mutations. As the progress in flower developmental genetics, the ABC model was expanded to the ABCD model with the introduction of D class genes for ovary identity. More recently, a A-E model was proposed and will be discussed in this short review.

Two pathways have been proposed for the biosynthesis of ABA: the ‘direct pathway’ and ‘indirect pathway’. In the direct pathway, which operates in some fungi, ABA is derived from farnesyl diphosphate; in indirect pathway, ABA is produced from the oxidative cleavage of carotenoids. The first committed step for ABA biosynthesis in plants is the oxidative cleavage of a 9-cisepoxycarotenoid(C40) to produce xanthoxin(C15) and a C25 by-product(Fig.2). Xanthoxin is then oxidized to a ketone by an NAD-requiring enzyme. Consequently, there is a nonenzymatic desaturation of the 2'-3' bond and opening of the epoxide ring to form abscisic aldehyde. In the final step of the pathway, abscisic aldehyde is oxidized to ABA. These endogenous enzymes such as zeaxanthin epoxidase(ZEP), 9-cis-epoxycarotenoid dioxygenase(NCED) and aldehyde oxidase(AO) may play key roles in the regulation of ABA biosynthesis in higher plants.

Abstract Many melon vegetables are included in Cucurbitaceae, and in vitro culture of Cucurbitaceae is very important. This paper reviewed recent research progress on tissue culture,somatic embryogenesis, anther culture, protoplast culture and somatic hybridization, as well as genetic transformation of Cucurbitaceae in China. The prospects of in vitro culture, genetic transformation and breeding of these plants were predicted.

A review was made of published literature in the recent years on the antifungal metabolites in higher plants. The metabolites mainly include terpenes, alkaloids, flavones, phenols, quinines, phenylpropanoids, coumarins and lignans. The characteristics of antifungal constituents in the families of Gramineae, Leguminosae, Rosaceae, Compositae and Cruciferae were emphasized. A brief conclusion and some suggestions for the further research of antifungal substances were also outlined.

This report of oil plant Camelina sativa (L.) Crantz reviews its planting history, biological characters, seed composition, cultivated methods, resistance to disease and insect, and product utilization. The plant has high ability to endure drought and to resist to disease, insect, and weed. As a low-put economic crop, Camelina sativa has a extensive prospect for planting.