Male Sterile Lines of Zinnia elegans and Their Cytological Observations

In order to find out a new pathway for utilizing heterosis of Zinnia elegans and accelerate breeding process, the mechanism of anther development of a male sterile line was explored. Backcross, sibmating, selling of fertile plants and testcross with inbred lines were analyzed and identified in the field, and cytology was observed. Recessive nucleus male sterile line AH209AB capable of being a maintainer was obtained by successive backcrosses with male sterile plants and fertile F1 plants as male parents. Cytological and anatomical studies indicated that： （1） The wall of normal anther was constituted of four layers of cells such as epidermis, powder chamber wall, middle level and tapetum cells. The process in meiosis of pollen mother cell in Zinnia elegans was normal and cytoplasm divided simultanously. Mature pollen grain was tricellular type. （2） The petal of male sterile plant degraded as a thread-like structure, the stamens were villiform in appearance and no pollens were formed. The result showed that the anther of male sterile plant no longer proceed to differentiate spore mother cell and the pollen sac after the formation of the tissue of sporogenous cells, there was no evident boundary between tapetum cell, middle lamella and inner wall of PMC, tapetal cells did not develop from the very beginning. So the abortion type was completely structural male sterility. The male sterile line belongs to non-sporange male sterile type and is of great use in F1 seeds production.

Construction and Analysis of Suppression Subtractive cDNA Library from Fertile Disk Floret Buds of Zinnia elegans

In order to isolate genes related to anther development and understand molecular basis of male sterility,cDNA library of Zinnia elegans was constructed using suppression subtractive hybridization（SSH） approach.672 different expressed clones were selected from the fertile disk floret buds.PCR results showed that cDNA inserts were ranged from 100 to 750 bp.303 positive clones screened by dot-blot hybridization were sequenced.273 out of 303 sequenced clones produced readable sequences;these sequences represent 87 non-repetitive sequences.The homology alignment showed that 76 expressed sequence tags（ESTs） had functional annotations in GenBank,the other 11 ESTs without any homology to the known gene.In addition,87 ESTs were divided into 17 groups according to MIPS of Arabidopsis thaliana database.Sequence data from the cDNA library have been deposited with the GenBank under the accession numbers GT067016-GT067085.As an important result in this study,7 genes related to anther development were isolated.Results from semi-quantitative RT-PCR showed 6 genes were expressed only in disk florets of fertile plants compared with that of male sterile plants.These ESTs obtained provide important clues for further isolation and identification of fertility-related genes in Z.elegans.

Application Effect of Sludge Extract in the Planting of Zinnia elegans

[Objectives] The research aimed to study the effect of sludge extract on the growth of Zinnia elegans, and evaluate its possibility of application. [Methods] Z. elegans was taken as research object, and the effect of sludge extract on the growth indicators of Z. elegans was studied. [Results] The sludge extract can obviously promote the growth of Z. elegans, and the growth indicators were significantly improved when compared with the control group. The application effect was close to that of foliar fertilizer purchased in the market. In each treatment group, the low concentration of sludge extract did not significantly promote the growth of Z. elegans, while too high concentration could inhibit its growth, and the optimal dilution ratio was 600 times. [Conclusions] Further preparation of amino acid foliar fertilizer from sludge extract and its application in planting garden plants can realize the resource utilization of sludge and has a good development and application prospect.

Downregulation of the Basic Peroxidase Isoenzyme from Zinnia elegans by Gibberellic Acid

Hypocotyl formation during the epigeal germination of seedlings is under strict hormonal regulation. In a 3 d old Zinnia elegans seedling system, gibberellic acid （GA3） exerts an opposite effect to that exerted by light on hypocotyl photomorphogenesis because GAz promotes an etiolated-like growth with an inhibition of radial （secondary） growth. For this reason, the effect of GA3 on the basic peroxidase isoenzyme from Z. elegans （ZePrx）, an enzyme involved in hypocotyl lignin biosynthesis, was studied. The results showed that GA3 reduces ZePrx activity, similarly to the way in which it reduces seedling secondary growth. This hormonal response is supported by the analysis of the ZePrx promoter, which contains four types of GA3-responsive cis.elements： the W Box/O2S; the Pyr Box; the GARE; and the Amy Box. Taken together, these results suggest that ZePrx is directly regulated by GA3, with this effect matching the inhibitory effect of GA on the hypocotyl secondary growth.

真空处理和花蕾时期对百日草花序浸染法的影响

在百日草(Zinnia elegans)S5头状花序形态和子房细胞学观察的基础上,通过不同配比农杆菌重悬液、真空处理方法和头状花序发育时期对非组培的花序浸染法进行百日草转化技术适用性探索。结果表明,S5花序发育的外部形态和细胞学观察发现小花蕾7及以后发育时期的心皮处于开放状态。农杆菌重悬液为1/2 MS+0.03%Silwet L-77+10%蔗糖+0.01 mg/L 6-BA(OD600 nm=0.4)处理蕾3头状花序得到0.35%的转化率。真空断续处理有利于转化率的提高,较好的处理组合是真空断续2 min+30 s处理蕾5至蕾7头状花序,收获其中的小花蕾7至蕾9的转化率可达3.23%~5.00%。

华南地区番木瓜林下套种百日草花海实践

蔬果采摘和花海观赏是现代休闲农业园区的重要组成部分,也是收入的重要来源。为增加休闲农业园区的收益,在深圳利用采摘空档期尝试了番木瓜林下套种百日草营造林下花海,并从整地、播种、管养、运营等方面总结经验,分析投入产出,以期为采摘林套种草本花海新模式在华南地区的应用提供参考。