土塘对杂交石斑鱼苗种生长的影响

本实验通过分析比较土塘和室内水泥池杂交石斑鱼苗种培育的水质指标,研究土塘水质各因子对杂交石斑鱼苗种生长的影响。结果表明,土塘海水水质各因子对仔鱼生长的影响各不相同:氨氮离子、亚硝酸盐、水温、盐度、细菌含量对仔鱼生长的影响较小;硫化氢浓度、pH值、透明度对杂交石斑鱼仔鱼生长的影响较大。初步论证了土塘作为人工培育杂交石斑鱼的方法是可行的。

Seed germination and seedling development of Prunus armeniaca under different burial depths in soil

A semi-greenhouse study was conducted to understand the effects of soil burial depth on seed germination and seedling development. The seeds of wild apricot （Prunus armeniaca） were buried at the soil depths of 0-cm, 4-cm, 8-cm, and 12-cm, respectively, to simulate the seed hoarding behavior of rodents in the field. The results revealed that the rates of seed germination and established seedlings from buried seeds were both the highest in 4-cm burial depth group, and then decreased with increasing soil depth. The number of rotten seeds increased in deeper burial depth. It is unfavourable for seed germination at 0-cm burial depth （i.e., seeds were laid on soil surface）. There was insignificant effect of burial depth on growth of established seedlings. The results from this study indicated that proper burial depth in soil would be helpful for the seed germination and seedling growth. The seedlings derived from buried seeds at shallower depth （4 cm） in this research have advantage in their early development.

Effects of Pb Stress on Seed Germination and Seedling Growth of Two Weed Species Seeds

Objective] The aim was to investigate the effects of Pb stress on seed germination and seedling growth of Chenopodium glaucum and Chenopodium serot-inum L. [Method] With C. glaucum and C. serotinum as the study objects, the ef-fects of different concentrations of Pb on their seed germination and seedling growth, as wel as on the leaf SOD, POD and CAT activity were studied primarily. [Result] The germination potential of both the two kinds of weed seeds increased first and then decreased with the increase of Pb concentration. The germination po-tential of C. serotinum and C. glaucum seeds reached the peak at Pb concentration of 25 and 50 mg/L, respectively. With the increase of Pb treatment concentration, the germination rate, germination index and vigor index of C. serotinum and C. glaucum seeds decreased, and their bud length and root length also reduced gradu-al y. ln overal , the leaf SOD, POD and CAT activity of C. glaucum and C. serot-inum_ seedlings increased first and then decreased with the increased treatment concentration of Pb. The leaf SOD and POD activity of C. glaucum and C. serot-inum seedlings reached the maximum at Pb concentration of 200 and 100 mg/L, respectively, and the leaf CAT activity reached the maximum at Pb concentration of 100 mg/L. [Conclusion] The two Chenopodium species had strong tolerance to Pb stress, and they could be used as alternative accumulator plants of soil Pb contami-nation.

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Brassica napus L.

To investigate the effects of the heavy metal cadmium （Cd） on seed ger- mination and seedling growth of Brassica napus L., 25 B. napus lines with different genetic background were treated with four concentrations （0, 1, 5 and 10 mg/L） of Cd, and then, their germination potential, germination rate, seedling length, main root length, seedling fresh weight, and seedling dry weight were measured. The re- sults showed that the response of the B. napus lines to Cd stress was different. With the increase of Cd concentration, the relative germination potential and relative seedling rate increased first and then decreased, and reached the maximum levels when the Cd concentration was 5 rag/L. The inhibitory effects of Cd stress on seedling growth indices in a decreasing order were root length〉seedling length〉 seedling fresh weight〉seedling water content. There were extremely significant differ- ences in the relative root length, relative seedling length, relative seedling fresh weight and relative seedling water content among the B. napus lines treated by dif- ferent concentrations of Cd, while there were no significant differences in the rela- tive germination potential and relative seedling rate among the lines, except that the relative seedling rate was significantly different among the lines treated by 5 mg/L Cd. The results suggested that seedling growth was more sensitive than seed ger- mination to heavy metal stress.

Effect of trace elements on growth of Pinus tabulaeformis seedling

The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000-2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%~19% for the seeds treated with 1% concentration and 12%~14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.

Effects of Liquid Seaweed Bio-organic Fertilizer on Seed Germination and Seedling Growth of Vegetables

[Objective] This study aimed to investigate the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of different vegetables. [Method] Serial dilution concentrations of liquid seaweed bio-organic fertilizer were prepared for seed soaking and pot incubation of cucumber, tomato and chili, to ob- serve the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of vegetables. [Result] Compared with the control, germination rate of cucumber and tomato seeds applied with 600-fold liquid seaweed bio-organic fer- tilizer varied significantly; germination rate of chili seeds applied with 400-fold liquid seaweed bio-organic fertilizer varied significantly; germination energy and germination index of chili seeds applied with different dilution concentrations of liquid seaweed bio-organic fertilizer presented no significant differences. In addition, 200-fold and 400-fold liquid seaweed bio-organic fertilizer significantly improved the root length, plant height, plant fresh weight, plant dry weight, chlorophyll content and leaf area of cucumber, tomato and chili seedlings; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content and leaf area of cucumber seedlings varied significantly compared with the control, but no significant differences were observed in plant height, plant fresh weight and plant dry weight; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content, plant height, plant fresh weight and plant dry weight of chili and tomato varied sig- nificantly compared with the control, but no significant differences were observed in leaf area. [Conclusion] Soaking vegetable seeds with liquid seaweed bio-organic fer- tilizer can significantly improve seed generation rate and seedling growth.

Effects of Bamboo Vinegar on Seed Germination and Seedling Growth of Different Flue-cured Tobacco Varieties

[Objective] The present experiment was conducted to study the effects of bamboo vinegar on seed germination and seedling growth of different flue-cured to- bacco varieties, so as to provide some references for its application in tobacco pro- duction. [Method] By using indoor culture dish method and greenhouse seedling- raising plate culture,four different concentrations of bamboo vinegar dilution （50, 100, 200 and 400 times）were designed and clean water was used as the control （CK）. The germination indices of Yunyan 97, Guiyan 2, Jiucaiping 2 and Bina 1 were de- termined after seed germinating. The seedling growth indices of Yunyan 97 were investigated after 10 days of spaying bamboo vinegar on seedling leaves at the 3r~ time. [Result] Compared with CK, different bamboo vinegar dilutions could inhibit the seed germination and seedling growth of all flue-cured tobacco varieties. The seed germination rate and index, vigor index, whole length, root length, stem length and fresh weight of seedlings of all varieties presented decreasing trend to varying de- grees, moreover, most of them reached significant level. Compared with CK, spray- ing different concentrations of bamboo vinegar dilution at the seedling stage could improve the quality of seedlings. In all bamboo vinegar treatments, the plant height, the maximum leaf length and root volume under 100 times dilution treatment were the highest with 3.36 and 10.14 cm, and 0.92 ml, respectively. And the stem girth, dry weight and the maximum leaf width of seedlings under 400 times dilution treat- ment also showed the highest with 1.82 cm, 0.262 g and 5.74 cm, respectively. [Conclusion] Supplying different concentrations of bamboo vinegar solution on culture dish could inhibit the seed germination and seedling growth of flue-cured tobacco, while spraying 100-400 times bamboo vinegar solution to leaves could promote the seedling growth and improve the quality of Yunyan 97 to varying degrees.

Effect of Different Treatments on the Germination and Seedling Growth of Firmiana simplex

With Firmiana simplex （L.） W. F. Wight as an experiment material, the effects of different concentrations of GA3 （Gibberellin A3）, SA （Salicylic acid） and NAA （1-Naphthalene acetic acid） and stratification on the germination rate of seeds were studied firstly, and then the effects of GA3 and NAA on seedling growth were analyzed. The results showed that the germination rate could be improved by 0.075 g/L SA and stratification markedly. It was indicated by the experiment that the growth of the main root and main stem could be promoted by 0.050 g/L and 0.077 g/L NAA, respectively. However, the leaf length and leaf width decreased significantly in the GA3 and NAA treatments.

Study on Cadmium Tolerance of Seed Germination and Seedlings Growth of Different Rice Varieties

The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germination rate, shooting index, vigor index, seedling and shoot lengths, and fresh weights. The results showed that as Cd concentration grew, seed germination and seedling growth kept increasingly inhibited; germination index, vigor index, root length, shoot length and fresh weights went down; inhibition effects on seed germination and seedling growth were conventional rice〉two-line hybrid rice〉three-line hybrid ,rice. Shanyou 9588, Tianyou 998, Chuanxiang 8, and Y Liangyou 1 performed ~rongly in Cd tolerance; C Liangyou 651, Nei 5 You 263, Xiangwanxian 16, Huanghuazhan, Xiangwanxian 13, and Zhunliangyou 527 performed poorly in Cd tolerance, and Cd tolerance of rest treatments were moderate.

Effect of pre-sowing treatments on germination and initial seedling development of Albizia saman in the nursery

Albizia saman （Jacq.） F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed （at the distal end of the seed） （T4） provides the highest （50%） seed germination. The second highest germination （42%） was obtained for the seeds treated with immersion in cold water for 24 h （T1）. Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control （Ta）treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed （at the distal end of the seed） and T1 （Seeds immersed in cold water for 24 h） may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.

Seed Germination and Seedling Growth of Idesia polycarpa

[Objective] This study was conducted to characterize the seed germination and seedling growth of Idesia polycarpa. [Method] After 3-5 h of soaking in 5% baking soda solution, the waxy outer layer of the seeds was rubbed off. Then, the seeds were mixed with fine sand and evenly sown on seedbeds. Germinated seeds were counted to calculate germination rate. Seedlings at two-or three-leef stage were transplanted, and their phenophases were observed and recorded. Height and ground diameter of the seedlings were monitored in the following three years. [Result] The seed germination rate was increased to 20% by soaking in 5% baking soda solution. The yearly seedling height growth of L polycarpa increased with the increase in seedling age. The monthly seedling height growth from August to October was much higher than in other months in the first year, and the growth in seedling height in the three months accounted for 79% of the total increase in that year. The seedling height grew rapidly from May to July in the following two years. In detail, the increase in seedling height from May to July accounted for 87.94% of the total increase in the second year, and 74.16% of the total increase in the third year. The monthly seedling height growth peaked in May in the two years. The yearly growth in ground diameter of I. polycarpa seedlings also increased with the increase in seedling age. The monthly growth in ground diameter from July to September was much higher than in other months in the first year, and the increase in ground diameter in the three months accounted for 80% of the total increase in that year. In the second and third years, the monthly growth in ground diameter from July to October was much higher than in other months. The increase in ground diameter in the two months accounted for 76.89% of the total increase in the second year, and 61.23% of the total increase in the third year. The monthly growth in ground diameter peaked in August in the two years. [Conclusion] The results will provide a theoretical basis for the development and popularization of L polycarpa in Chongqing and surrounding provinces and cities.

Effects of Trichoderma harzianum YC_(459) and soil types on seed germination and seedling growth in rock slope restoration

We carried out experiments with various concentrations of Trichoderma harzianum YC459 in different soil types(forest soil, mixed soil,merchantable soil, and leaf mold soil) to evaluate its effect on seed germination and seedling establishment of four species(Festuca arundinacea Schreb., Dianthus barbatus var. asiaticus Nakai,Lespedeza cyrtobotrya Miq., and Parthenocissus tricuspidata Planch) for rock slope restoration. We also investigated the use of drilled slanted holes on the rock slopes for seedling establishment. The results showed that T. harzianum concentration had significant effects on seed germination, seedling growth, and seedling survival for all the species with different soil types. Seed germination and survival rates peaked at 5% T. harzianum concentration with leaf mold soil and decreased as T. harzianum concentration increased from 5% to 10%. Seedling survival rates of all four species were generally lowest at 0% T. harzianum concentration in all soil types.The height of F. arundinacea and L. cyrtobotrya peaked at 5% T. harzianum concentration whereas that of D. barbatus and P. tricuspidata peaked at 10%T. harzianum concentration. We concluded that 5% T. harzianum concentration with leaf mold soil is appropriate for seed germination and seedling survival rates of most species, thus enhancing seedling establishment. Practical application of the findings of this study will contribute in the vegetation restoration of steep rocks in mountain environments.

A Preliminary Study on Allelopathy of Pogonatum inflexum Aqueous Extract

[Objective] The aim was to study the effects of Pogonatum inflexum aqueous extract on wheat seed germination and seedling growth to cladfy the possible allelopathic effects. [Method] With distilled water as control, wheat seeds were cultivated with the aqueous extract of P. inflexum gametophytes. After 7 days, the germination rate, root length, bud length, biomass and vigor index were determined. [Result] Middle and low concentration of P. inflexum aqueous extract significantly promoted the seed germination and seedling growth of wheat （P〈0.05）. With the in- creased concentration of the aqueous extract, the indexes all increased first and then decreased. The effect intensity of P. inflexum aqueous extract on root growth and biomass of wheat was stronger than that on bud growth. [Conclusion] Low-concentration P. inflexum aqueous extract promoted, while high-concentration Po inflexum aqueous extract inhibited the seed germination and seedling growth wheat.P, inflexum has a certain allelopathic potential, but the specific mechanism needs to be revealed and clarified by further research.

Effects of Extracts from Albizia （Fabaceae） Endemic Species of Madagascar on Vegetable Seedling Development

The effects of extracts from five Albizia （Fabaceae） endemic species from Madagascar （A. arenicola, A. boivini, A. bernieri, A. polyphylla and A. tulearensis） were tested on vegetable seedling development. Crude extracts were obtained through cold or hot extraction methods on dried powdered seeds, seed teguments, leaves or empty pods. They were thereafter purified using techniques based on physicochemical properties of active substances. Assays were carried out on seedling growth of Monocotyledons and Dicotyledons representatives. Results showed that all extracts exerted significant dose dependent inhibition on epicotyl and hypocotyl growth. However, some extracts exhibited a slight stimulation effect at low doses. Moreover, A. arenicola crude extract （E23） slightly inhibited axillary bud growth, while A. tulearensis crude extract （ET1） showed a stimulation effect. According to preliminary phytochemical screening results, these effects might be due to saponins or alkaloids.

Methods of Testing Seed and Seedling Physiological Traits for the Improvement of Rapeseed Yield Stability

The presented work is based on laboratory testing of seed germination speed, emergence and seedling growth under different stress conditions simulated by subnormal water revel, extreme high and low temperatures. It allows one to eliminate the plant materials （initial breeding materials and cultivars） which do not tolerate extreme temperatures and temperature changes during germination, have low water use efficiency and is intolerant to abiotic stressors all right at the seed level. It was confirmed that these genotypes also have poor t^eld emergence and initial root growth implications for further vegetation periods, mainly for over wintering and spring regeneration which has significant influence on the yield. The method also represents the tool for screening genetic resources with the resistance to the abiotic stressors and this technology process is also acceptable for other crops. The results confirm the importance of the seed and root characteristics for crop production. The deteriorating quality of soil in recent years, increasing variability of weather and long periods of drought directly support the need to intensify activities in this research. Obtained results also show the influence of seed quality characteristics on roots and above ground parts of the plant. A relationship exists also vice versa.

Herbicidal Activities of Seven Native Plants on the Germination and Growth of Phalaris minor, Echinochloa crusgalli, Portulaca oleracea and Lactuca sativa

Plant extracts could turn out to be herbicides used in weed control. We evaluated the herbicidal effect of seven plants from the Al-Qassim Region of Saudi Arabia on germination and growth of Phalaris minor, Echinochloa crusgalli, Portulaca oleracea and Lactuca sativa. In the laboratory, plant extracts at 5, 10, 20 and 40 g/L inhibited the germination and seedling growth of test seeds. P. minor and P. oleracea were more sensitive to the extracts than L. sativa and E. crusgalli. The germination of either P. minor or P. oleracea were completely inhibited by Prosopisjuliflora at 10 g/L and by Rumex vesicarius and Teucrium baccatus at 20 g/L. Extract of Pulicaria undulate completely inhibited germination of target seeds at concentrations ranged from l 0 g/L to 40 g/L. The rank order of bioactivity was Prosopis jul（17ora 〉 Pulicaria undulata 〉 Rumex vesicarius 〉 Withania somnifera 〉 Teucrium baccatus 〉 Artemisia monosperma 〉 Anvillea garcinii. In the greenhouse trial, the extracts of seven plant species at 30, 60 and 90 g/L reduced growth of six-weeks-old target plants. Anvillea garcinii and Prosopisjuliflora showed the greatest effects. At 90 g/L, the reduction in the growth of target species reached between 20% and 30% for Anvillea garcinii and between I 1% and 25% for Prosopis juliflora. Overall, Prosopis juliflora, Pulicaria undulata, Anvillea garcinii and Rumex vesicarius had potential for use as natural herbicides or for development as novel plant-derived herbicides.

Toxicity to wheat seed germination and seedling growth of copper stress

Toxicity of the different concentration of Cu^2＋ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that： The correlation between the content of Cu^2＋ in medium and the germination and growth of the seedlings is significant （P〈0.01）. The effect of Cu^2＋ to the germination, plant height, fresh weight, dried weight and the chlorophyll mount of the wheat seedling was stimulated under lower concentration of Cu^2＋ and was inhibited under higher concentration. With the increase of the Cu^2＋ concentration in the culture solution, the germination and growth of the seedlings was inhibited. The perfect positive correlation between the Cu^2＋ content in the plant and that in the culture solution was noted. Most of Cu^2＋ was concentrated in the root, and only a small amount was migrated to the aerial part of the wheat seedling. The sensitivity of each index to the Cu^2＋ concentration was ranked as follows： the Cu^2＋ content in the plant〉chlorophyll-a〉the ratio of chlorophyll-a to chlorophyll-b〉total chlorophyll〉plant height 〉germination〉fresh weight〉root elongation〉 chlorophyll-b 〉dried weight. The Cu^2＋ content in the wheat plant was the most sensitive index to the Cu^2＋ concentration in the culture solution.

Effect of Seed Sizes on the Growth and Establishment of Seedlings of Sheanut Tree （Vitellaria paradoxa）

Seed size can influence germination, emergence and further development of plants to produce high yield. Therefore, pot trial was conducted to assess the effects of seed sizes on growth and establishment of sheanut tree seedlings （Vitellaria paradoxa） in tlae southern Guinea savanna of Nigeria. Seedlings produced from large sized seed had higher germination （80%） than those from medium （70%） and small （65%） sized seeds. Number of days to emergence of seedling from large-sized seed planting was 30 days, 49 days for small- and medium-sized seeds. Large sized seeds had higher N, P, K, Ca and Mg contents compared with small and medium sized seeds. Generally, seedlings from large sized seeds had about 1.5 times more leaves than medium sized seeds and about 2 times more leaves than small sized seeds at 8, 10, 12, 14 and 16 weeks after planting （WAP）. Seedlings from large sized seeds were taller and had larger stem girth （at 16WAP） than those from medium sized seeds. Variations in seedling growth from seed sizes could be of operational importance in nursery management as seeds can be sown according to size to improve uniformity. However, further studies to ascertain if the superior growth of seedlings from large sized seeds will lead to higher yield is recommended.

Calcium Addition Affects Germination and Early Seedling Growth of Sweet Sorghum under Saline Conditions

[Objective] This study aimed to determine the interactive effects of supple- mental Ca amendment and salinity on germination of sweet sorghum seeds in saline solution culture medium, and investigate the effects of different combinations of Na/Ca ratio in saline soils on the early growth of sweet sorghum plants. [Method] A germi- nation test and a greenhouse pot experiment were conducted to assess the interac- tive effects of calcium addition to culture medium on the germination and seedling growth of sweet sorghum （Sorghum saccharatum Moench） in saline soils with a range of NaYCa ratios. In the germination test, seeds were treated with different combinations of five calcium levels [0, 5, 10, 15, and 20 mmol/L Ca（NO3）2] and five salinity levels （0, 50, 100, 150, and 200 mmol/L NaCI）. In the greenhouse experi- ment, seeds were sown in potting soils containing 3 salinity levels （2.3, 4.7 and 7.0 dS/m） and three Na：Ca ratios （10：0, 10：1, and 5：1）. [Result] In the germination test, Ca addition at 5 mmol/L promoted germination by 5.5%, 9.9%, and 17.0% at the 3.4, 6.7 and 10.1 dS/m salinity levels. The higher Ca level （10 mmol/L） also in- creased germination by 9.1% and 7.8% at the 3.4 and 6.7 dS/m salinity levels. Then even higher Ca addition at 15 and 20 mmol/L appeared to promote germina- tion when culture media had high salinity （10.1 and 13.4 dS/m）. In the greenhouse pot experiment, saline soil amended with supplemental Ca at the 2.3 and 4.7 dS/m salinity levels significantly promoted early seedling growth, with an increase of 6.8% to 28.2% in plant height and 14.3% to 67.9% in whole plant weight. From 28 to 42 d after seeding, the relative growth of seedling was increased by Ca addition, with a reduction of 49.5% to 66.0% in plant height and 4.8% to 61.9% in whole plant weight. From 42 to 56 d after seeding, however, the relative growth of seedling was significantly inhibited by Ca amendment. [Conclusion] Results of this study indicate that appropriate supplemental Ca could improve sorghum germination and early seedling growth in saline soils.

Effect of Seed Drying on Germination Behavior and Seedling Growth of Sweetsop （Annona squamosa）

An experiment was conducted at the Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi （KNUST） Ghana from September, 2009 to April, 2010, to determine the most appropriate drying method, as a post harvest practice, that would ensure high percentage germination ofAnnona squamosa seeds and its subsequent effect on seedling growth. The seeds were sun-dried, air-dried under shade or kept in the fresh state. Five treatments were used, namely, Freshly Sown seeds （Treatment 1, control）, Seeds Air-Dried under Shade for one day （Treatment 2）; Seeds Sun-Dried for one day （Treatment 3）; Seeds Air-Dried under Shade for three consecutive days （Treatment 4）; Seeds Sun-Dried for three consecutive days （Treatment 5）. The experiment was arranged in a Completely Randomized Design （CRD） and replicated three times. Drying of Annona squamosa seeds had significant effect on earliness and number of seeds germinated. Air drying under shade and sun-drying for three consecutive days improved earliness to germination （26 days after sowing） and percent total germination but air-drying under shade had better effect on total seed germination, achieving 90% germination in 42 days after sowing. Furthermore, the prevailing ambient temperature of 30 ℃-32 ℃ enhanced germination of Annona squamosa seeds. The study concluded that for optimum germination, seeds of Annona squamosa should be either air-dried or sun-dried for three consecutive days and be incubated in an ambient temperature range of 30 ℃-32 ℃. In terms of growth, seedling growth in leaf production was better from seeds sun-dried for three consecutive days.