The conventional breeding, genetic engineering, somatic hybridization and anther and microspore culture of Petunia hybrida Vilm. were reviewed in this paper. Conventional breeding has been the main method for new cultivar development by which a lot of new cultivars have been produced. There has been intensive research on genetic transformation and some new cultivars were already produced through this way. Although somatic hybridization and anther culture have not gained new cultivars in Petunia, they show promising potential for Petunia breeding.

This paper reviews advances and application of genetic improvement which include conventional breeding mutagensis and biotechnology and germplasm resources on collections,research and evaluation for Dendranthema morifolium. Present problem and some suggestion about the prospects of development are discussed.

In present paper, the natural existing forms of chlorine (Cl), the relationship between chloride and plant growth and development, and the mechanisms of chloride anion absorption and transportation in plants were introduced. The kinds and characteristics of Cl- channels and CLCs proteins were reviewed. The responses of plants to Chlorine deficiency and excessiveness, the possible physiology and molecular biological mechanisms of Chlorine tolerance in plants were also discussed.

Abstract Evaluation of heat tolerance in crops is the basis for studying heat tolerance mechanisms and breeding heat-tolerant varieties. In this paper, the foundation, methods and indexes for evaluation heat tolerance in crops are reviewed, and the research direction of evaluation of heat tolerance in crops is prospected.

This paper reviewed recent advances in physiological mechanisms of rice quality development. The main contents include the properties of source and sink, the enzymes involved in starch biosynthesis, the shape and structure of starch granule and the pasting character of starch during the formation of grain quality. It is suggested that physiological studies of seed development are essential to reveal the formation mechanisms of rice quality.

Leaf recognition is an important step for plant computerized identification, especially for field living plants. Previous researches were mainly focused on leaf recognition by utilizing the peripheral contour of the leaf while ignoring the leaf venation that actually contains important genetic information.Conventional thresholding-based methods cannot extract the information accurately due to high diversity of leaf veins. In this paper, an approach based on artificial neural network learning is proposed to extract leaf venation. Ten features including edge gradients, local contrast and statistical features are extracted from a window centered at the image pixel and used to train a neural network classifier. Compared with conventional thresholding-based methods, the trained neural network is capable of extracting more accurate modality of leaf venation for subsequent leaf recognition.

12-year-old ‘Muscat Hamburg’ grape was used as a experimental material to study the enlargement effect of streptomycin on seedless berry and its residue in fruit. The results indicated that the rate of seedless was up to 96% if the clusters of flowers were soaked with mixture of GAs 50mg.L-1 and streptomycin 400 mg.L-1 before 3 days when the flowers is blooming fully. The residual amount of streptomycin in fruit at the tenth day after treatment decreased as 10% as that of beginning, and less than 1 mg.kg-1 when the fruit matured. Date analysis on the base of the gray system theory indicated that fruit was enlarged and its quality was improved when ‘Muscat Hamburg’ was soaked with CPPU 5 mg.L-1 and GAs 50 mg.L-1, GAs 100 mg.L-1 or GAs 50 mg.L-1 and CPPU 5 mg.L-1 2 weeks after full blooming fully.

A technique for separating the pigment-protein complexes from brown algae Undaria pinnatifida had some improvement in this work. Pigment-protein complexes were isolated by centrifugation on discontinuous sucrose density gradient of the SDS-treated thylakoid membranes. The best separation was obtained with detergent SDS (SDS:Chl=20:1, solubilized 20 min at 4℃), and sucrose density gradients (10%,15%,20%,30%,40%,50%,60% W/W). The 40% sucrose layer represented photosystemⅠ (PSⅠ) complex. In contrast with red algae, the results suggested that PSⅠ complex from Undaria pinnatifida had no symbol of 730 nm fluorescence peak.

Gracilaria lemaneiformis, an economical seaweed containing a lot of polysaccharide in the cell, was homogenized by means of the combination of the mechanical grinding and ultrasonic disruption, and then the thylakoid membrane was purified by the sucrose gradient centrifugation. The intrinsic chlorophyll-protein complexes with different pigment composition were isolated by the centrifugation after the purified thylakoid membrane had been fragmented with the non-ionic detergent, Triton X-100. Differential spectrophotometry of these isolated chlorophyll-protein complexes showed that the photosystemⅠwas obtained, and the photosystemⅡ was detected to have the activity of photo-reduction for DCIP. All these results indicated that the photosystem particles with activities can be obtained although the marine algal membranes are extremely resistant to attack by detergents.

Induction conditions of Crocus sativus L. callus were optimized. MS medium was optimal for shoot callus induction while B5 medium was optimal for leaf and flower callus induction. 18℃, 25 ℃ and 21℃ were the optimal temperature for callus induction of shoot, leaf and flower, respectively.Light was positive factor for leaf callus induction but negative for shoot and flower induction. Naphthaleneacetic acid (NAA, 1.5-2.0 mg.L-1) and 6-benzyladenine (6-BA, 0.25 mg.L-1) were the optimal hormones for callus induction. Under the optimized conditions, the induction rate reached 60% for shoot callus, 80% for leaf callus, and 35% for flower callus. Using eyesight and HPLC methods, one callus line which gave rise to 1 677 mg.g-1 crocin and would not brown was obtained from 229 callus lines.

On signal transduction of self-incompatibility in Brassica, the signal molecule-SCR ligand is produced by the pollen grain, recognized by SRK receptor in stigmatic papillae, and transduced into a cellular response. The receptor-ligand pairs are two S locus-encoded highly polymorphic proteins that determine specificity of self-incompatibility. The ligand encoded by SCR gene is a small pollen coat protein present on the surface of pollen grains. The receptor localized to the plasma membrane of the stigmatic papillae on the surface of the pistil is encoded by SRK gene. During selfpollination, SCR interacts with its cognate receptor to activate SRK, which mediates the ubiquitination of substrates by ARC1. ARC1 functions downstream of the SRK. Ubiquitinated substrates, which may represent pistil compatible factors and normally promote pollen hydration, germination, and tube growth, are degraded by the proteasome/CSN, there by resulting in the response of selfincompatibility. In this paper, we give a detailed review about signal transduction of self-incompatibility in Brassica.

Orchidaceae is one of the largest families of flowering plants. DNA molecular marker techniques have been used in taxonomy, phylogenetic analysis between different species or varieties,and conservation. Orchidaceae has highly specialized morphological, structural, and physiological characteristics，it is an ideal material to study flower pigmentation and ovule initiation and development. In vitro flowering techniques of orchids provide a model system to study inflorescence differentiation and development. Flavonoid pathway was regulated by CHS and DFR gene in orchids.Flower bud formation and early flowering were controlled by DOH1 gene in Dendrobium. ACC synthase gene and PHAL.039 gene were most likely important regulators involved in ovule tissue initiation and development in Phalaenopsis. Genetic transformation has been reported in Phalaenopsis spp., Cymbidium spp., Oncidium spp., Dendrobium spp.， Doritis spp., and Vanda spp .Transgenic plants were produced from protocorm by bombardment or Agrobacterium mediated transformation.

Pteridophytes have a longer evolutionary history and have endured greater losses of phylogenetical information than spermatophytes. Therefore, reconstructing the evolutionary history of pteridophytes has been a challenge to systematists. Recently, combined molecular and morphological studies confirm the systematic positions of some lineages of pteridophytes. The emergence of early pteridophyte was traced back more than 400 million years ago, but many taxa lacked fossil records. So, questions remain unsolved regarding the origin time and pattern of pteridophyte and the internal phylogeny of its members. It is suggested that future studies of the origin and evolution of pteridophytes place emphasis on synthetic analysis of morphology, stratigraphic sequences, and multi-gene systematics.

Thylakoid lumen acidification induces high energy state quenching. The xanthophyll cycle-dependent excitation energy dissipation is regulated by thylakoid lumen acidification. Reversely,xanthophyll cycle can protect the thylakoid lumen against over-acidification. Over-acidification in thylakoid lumen induces instability of some luminal components, brings destructive effects on the photosynthetic apparatus, restricts normal turnover of the proteins, and induces photoinactivation of the PSⅡ reaction centers.

Somatic embryogenesis of coniferous species is used both as a means of propagation and as a valuable model system for investigating the structural, physiological, and molecular events occurring during embryo development. The whole embryogenesis is composed of three steps: induction and proliferation of embryogenic tissue, somatic embryo maturation, and somatic embryo germination and conversion. In past, attempts for improving the whole embryogenesis procedure were made almost during the maturation stage, because of the assumption that successful regeneration would be related to treatments provided during the development of the embryos. However, in the last several years, studies demonstrated that the early events in embryogenesis were also crucial for the completion of the overall embryogenic program, implemented by physiological, biochemical, and molecular studies. Manipulation of the culture conditions early in the process can increase both number and quality of the embryos. Furthermore, adjusting the medium can also enhance germination and conversion frequencies of somatic embryos matured. These new findings are important for improving induction and conversion frequencies in conifer somatic embryogenesis.

Thylakoid membrane, which is the place for photosynthetic reaction, is mainly composed of membrane lipids, membrane proteins and photosynthetic pigments. Low temperature can affect photosynthesis by affecting the construction of thylakoid membrane. In this paper, the function and composition of thylakoid membrane, and its change under low temperature stress are depicted. In addition, we also concerned the relationship between membrane lipids and photoinhibition, and recent studies on the relationship between chilling tolerance and trienoic fatty acids in plants by molecular biology methods.