Observation on Flowering Habit of Reverse Genic Sterile Rice FHS

[Objective] This study was to use reverse genic male sterile FHS better in field production. [Method] Low energy nitrogen ion beam was taken as a mutation source to conduct mutagenic treatment for indica rice 99-02 and the mutant FHS with special fertility that was isolated from their offspring. Some characteristics such as flowering habit and stigma exsertion rate of FHS were observed in this experiment. [Result] The reverse genic sterile rice FHS had an obvious peak flowering stage from 10:00 to 10:30, while the second peak flowering was from August 5 to August 10. Compared with PA64S, FHS flowered early and its flowering time was concentrated, showing that it is for seed propagation. The stigma exsertion rate of FHS was 85.8% and low exsertion rate was good for the purity of seed. [Conclusion] The reverse genic sterile rice FHS had good value in use, besides, it could also be used as comparison material for studying fertility alternation mechanism of photoperiod sensitive genic male sterile rice.

Research on Flowering Habits and Fertility of Gaozhou Common Wild Rice (Oryza rufipogon) in Lingshui of Hainan Province

[Objective] The paper was to explore the flowering habits and fertility of Gaozhou common wild rice （Oryza rufipogon Griff.） in Lingshui of Hainan Province. [Method] The flowering habits, pollen fertility and seed setting rate of Gaozhou common wild rice in Lingshui of Hainan Province were studied, and compared with the flowering habits of common wild rice in Hainan Province. [Result] Gaozhou common wild rice was able to flower twice a year. The first flowering stage was from mid-April to mid-June for about 60 d, and the daily peak flowering dates were from May 13 to May 22. The daily flowering time was mainly between 11：20 and 13：00, and the peak flowering was at 11：30. The second flowering stage was from late August to late October for about 45 d, and the peak flowering dates lasted from September 8 to September 18. The daily flowering time was mainly from 11：15 to 12：50, and the daily peak flowering was at 11：30. In both flowering stages, the panicles had the same flowering characteristics. The stigma exsertion reached a high value of 95.37% with single （46.23%） and dual （49.14%） stigmas exsertion respectively. A spikelet remained open for 1.5-2.5 h, the angle of spikelet opening varied from 29.9° to 32.4°. At the two flowering stage the average pollen fertility rates were 89.67% and 85.62%, the average seed setting rates were 58.81% and 55.79%, respectively. Hainan population flowered only once （from mid-October to mid-December）, this had significant difference with the performance of Gaozhou common wild rice which flowered twice a year. [Conclusion] The results provided basis for the research on gene flow frequency from transgenic rice to wild rice and its relationship with flowering habits of common wild rice.

Study on the Flowering,Fruiting and Seed Setting Characteristic of Wild Watermelon

[Objective] The flowering,fruiting and seed setting characteristic of wild watermelon were discussed in our paper.[Method] The flowering and fruiting habit of wild watermelon were observed,and the effect of different pollination methods（mixed pollination,single flower pollination and natural pollination）on fruit set percentage,weight per fruit,seeds per fruit and thousand-seed weight of wild watermelon were studied in our paper.[Result] Wild watermelon had few female flowers and low fruit set percentage;artificial pollination could not increase the fruit set percentage of wild watermelon obviously,but it could improve weight per fruit,seed yield and quality significantly,and mixed pollination was the best.[Conclusion] Our study could provide reference for the improvement of hybrid seed yield and quality of wild watermelon.

Study on the Characteristics of Florescence and Pollen in Lagerstroemia speciosa

[ Objective] To study the characteristics of florescence and pollen in Lagerstroemia speciosa. [ Method ] The process of flower opening and pollen tube germination of Lagerstroemia speciosa was observed and the pollen viability was determined through in vitro germination. [ Result] Sepals of L. speciosa started to diverge at 4：30 am, at 7： 00 am petals flatten up, anther diverged, and the stigma secreted a large number of mucus, it was the best time for artificial pollination. Boric acid and sucrose had a great effect on in vitro pollen germination of L. speciosa, the combination which made highest rate of pollen germination, was sucrose 150 g/L ＋ boric acid 20 mg/L ＋ CaCI2 10 mg/L. Through the fluorescence microscope, it was known that four hours after flowering, a lot of pollen grains germinated on the stigma, six hours after flowering, lots of pollen tubes entered the style and reached to 1/4 length of the style, 12 hours after flowering, pollen tubes concentrated into a beam forward, and reached to 1/2 length of the style, 24 hours after flowering, lots of pollen tubes entered the ovary in a beam and then fertilized and produced seeds. [ Conclusion] The results provide some basis for utilizing L. speciosa to breed.

Analysis on the Breeding and Major Traits of Wide-adaptability Indica CMS Line Yungu 3A

Breeding sterile lines is the key to the development of hybrid rice with wide adaptability. However, at present, few wide-adaptability sterile lines have been applied in production practice. In this study, Yungu 3A, a new WA-type Indica CMS line with good grain quality, was developed by hybridization between Yunfeng 66A with wide adaptability as female parent and F1 plants of Yunfeng 66B/D62B as male parent and continuous backcrossing. According to the results, the finally obtained lndica CMS line Yungu 3A has good plant type and leaf shape, strong tillering ability, excellent flowering habit, stable and complete male sterility with the sterile plant rate and pollen sterility rate of 100%, strong combining ability, high outcrossing rate, low sensitivity to light and temperature, and strong disease resistance, which was approved by Yunnan Provincial Crop Variety Appraisal Committee in 2013. Yungu 3A is conducive to the development of new hybrid rice combinations with good quality and wide adaptability, exhibiting a promising prospect of application.

The Evolution of Stinging Hairs and Other Characters in Nettle Family

Urticaceae Juss.is a large cosmopolitan family and taxonomically difficult group,partly because it encompasses a broad range of morphological diversity and many of the diagnostic characters（e.g.flower,achene.stipule,bract）require a microscope for accurate determination.Meanwhile,most Uriiceae species have stinging hairs which make them more difficult to collect and identify.As a result,the infra-familial classification of Urticaceae has been controversial for more than a century.A research group led by Prof.