The effect of constant and alternating temperatures,rinsing, stratification and fertilizer on germination of some weed species

The effect of constant and alternating temperatures, rinsing, stratification and application of a fertilizer solution on germination of 4 weed species was studied.The seeds of Matricaria chamomilla L. (mayweed) and Poa annua L. (annual meadow grass) achieved almost 100% germination under any condition. For Solanum nigrum L. (black nightshade) an alternating temperature was necessary for germination. The germination percentage of this species was also improved by a cold pretreatment. For Thlaspi arvense L. (stinkweed) a high germination percentage was obtained only when stratification, alternating temperature and a fertilizer solution were applied.     

旱地辣椒新品种筛选和适应性试验

2010~2011年对新育成和引进的11个辣椒新品种连续进行2年品种比较试验.试验结果表明,‘天椒9号’、‘航椒4号’和‘天椒0517’综合性状较好,产量高、抗病性强、商品性好、制干率高,适宜在甘谷县大面积推广种植.     

蓝丰等7个越橘品种在山东半岛的表现

经过7年多点试验,从103个越橘品种中筛选出适于山东半岛栽培的7个优良品种:蓝丰、公爵、达柔、埃利奥特、布里吉塔、瑞卡、斯巴坦。以上品种适应性强,丰产稳产,果实品质优。栽植2年生大苗,3年生每667m2产量均超过1000kg。已在当地发展以上品种越橘700hm2。     

不同萌发条件对线椒种子发芽特性的影响

为了解决生产中线椒种子发芽率不高的难题,对线椒种子分别进行不同浸种时间、不同催芽温度、不同质量浓度PEG-6000(聚乙二醇)和KNO3溶液浸种的单因子试验。结果表明:线椒种子在30℃下催芽、12h25℃清水浸种、10%PEG和0.15%KNO3溶液浸种的条件下,其发芽势和发芽率最高。     

Influence of fruit ripeness at the time of seed extraction on pepper (Capsicum annuum) seed germination

The influence of fruit ripeness (half ripe, fully ripe, overripe) at the time of seed extraction on seed germination behaviour, at 25 °C and 13 °C, was studied in two Spanish pepper cultivars for canning. Seeds from half ripe fruits had a poorer behaviour than those taken from fully ripe fruits, especially at 13 °C. Room ripening and overripening of half ripe fruits improved the germination behaviour of the seeds although this behaviour was poorer than that of seeds extracted from fully ripe fruits that were allowed to overripen. Overripening of fully ripe picked fruits slightly improved germination behaviour.     

Cardinal temperatures and thermal requirements for germination of cineraria seed

Summary

Effects of temperature on the rate of germination, measured as the reciprocal of the time taken for half the population to germinate, were studied in cineraria cvs Cindy Blue and Cindy Dark Red. The base, optimum and maximum temperatures for germination were derived respectively as 1.6, 24.8 and 37.8°C in cv. Cindy Blue, close to T_b = 1.9, T_o = 24.5 and T_m = 38.4°C in cv. Cindy Dark Red. All seeds of each cultivar had a common base temperature but needed different thermal times to germinate. Seed of cv. Cindy Dark Red began to germinate after ca. 30°Cd compared with 35°Cd required by cv. Cindy Blue. A thermal time of ca. 50°Cd was required for half the population to germinate in each cultivar and the thermal requirement for germination fraction >0.5 was similar in both cultivars. The base and maximum temperatures for germination were similar to those determined previously for leaf initiation and flower development.     

风选和引发处理对甜椒种子萌发及幼苗生长的影响

以甜椒种子为试材,通过风选和硝酸钾引发的方式,研究对甜椒种子萌发和幼苗生长的影响。试验设置1%硝酸钾溶液20℃下分别引发5、6、7 d,以未引发种子为对照,研究不同引发时间对甜椒种子萌发和幼苗生长的影响。结果表明,风选后甜椒种子千粒重较原种子显著增加3.25%,较不合格种子显著增加135.56%,不合格种子发芽势较CK处理显著降低43.42%,优选种子发芽率较CK处理显著提高5%。实验室发芽试验表明,发芽势各处理较CK处理显著提高58.49%、52.83%%、60.38%;发芽畸形数量各处理较CK处理显著降低73.91%、73.91%、69.57%;发芽指数各处理较CK处理显著提高了76.28%、69.87%、78.21%。穴盘育苗幼苗试验表明,在播种后47 d株高较CK处理显著提高13.21%,茎粗显著提高10.29%,叶片数显著提高9.09%,壮苗指数显著增加17.65%。综上可得,风选处理后,选用1%硝酸钾溶液,在20℃条件下,引发处理7 d能够显著提高发芽率和发芽势,促进幼苗生长,提高壮苗指数。     

赤霉素和复硝酚钠对辣椒种子萌发及幼苗活力的影响

为了提高辣椒幼苗素质并培育壮苗,用不同浓度的赤霉素和复硝酚钠处理辣椒种子,检测各处理的发芽率、幼苗质量和根系活力。结果表明,赤霉素和复硝酚钠浸种处理能促进辣椒种子萌发,提高幼苗的质量、壮苗指数和根系活力,低浓度处理的效果优于高浓度处理。综合来看,30～80 mg·L~(-1)赤霉素处理对促进辣椒种子萌发和提高前期根系活力的效果较好,10～70 mg·L~(-1)复硝酚钠处理对提高辣椒幼苗的质量和壮苗指数的作用比较显著。从培育壮苗方面考虑,10～70 mg·L~(-1)复硝酚钠处理效果最佳。     

不同辣椒品系(种)间种子萌发特性的比较

为筛选到优良的辣椒种质资源,满足进一步的遗传改良和育种的需要,选用111个辣椒品系(种),在漂浮育苗条件下,对这些品系(种)种子的发芽势、发芽率和发芽指数进行了研究。结果表明,‘gc2016-18’的发芽势、发芽率及发芽指数均为最高,分别为100%、100%、1.34;其次‘gx2016-4’‘gx2016-7’‘gx2016-20’‘gx2016-23’‘gc2016-47’和‘gv2016-2’的发芽势、发芽率和发芽指数均在90.00%~100.00%、90.00%~100.00%、1.00~1.34之间变动;发芽势超过80.00%的品系(种)占供试品系(种)的16.22%,发芽率超过80.00%的品系(种)占供试品系(种)的40.54%,发芽指数超过1.00的品系(种)占供试品系(种)的17.12%。     

Seasonal fluctuations of carbohydrate accumulation and metabolism of three tomato (Lycopersicon esculentum Mill.) cultivars grown at seven sowing times

Summary

Seasonal fluctuations of carbohydrate composition and concentrations, and the activities of related enzymes of three domesticated tomato cultivars including two large (Lady First and Momotaro) and one cherry-fruited (Minicarol) cultivar were examined at 45 d interval with seven sowing times. Fruits picked in cool seasons (early winter to spring seasons) had higher sugar concentrations than those of warm seasons. Fructose and glucose in nearly equal amounts were the predominant sugar in all seasons. Sucrose was present in trace quantities, but cherry tomato cultivar ‘Minicarol’ accumulated more than the large fruited types. Acid invertase (AI) (EC 3.2.1.26) activity was highest during cool seasons at the red stage of ripening, while fruit matured during warm seasons (May to August) had lowest activity. The sucrose synthase (SuSy) (EC 2.4.1.13) showed significantly higher activity during cool seasons in rapidly growing fruits followed by very low activity in mature non-growing fruits. There were no significant differences in sucrose phosphate synthase (SPS) (EC 2.4.1.14) activity. A highly significant positive correlation was found with sucrose accumulation in the case of SuSy but there was a negative correlation with AI activity and none with SPS. Therefore, in all growing seasons, AI and SuSy, rather than SPS could play a central role in regulating sugar accumulation in both large and cherry tomatoes. The result suggested planting season had no adverse effect on the trends of carbohydrate accumulation and metabolism in developing tomato cultivars, but in cool-season crops there is an improvement in fruit carbohydrate accmulation with more enhanced enzyme activities than in warm-season crops. These observations may help in selecting molecular genetic targets, and provide information for biotechnologists who wish to improve desired quality criteria of domesticated tomato genotypes.     

Promotion by 5-aminolevulenic acid of pepper seed germination and seedling emergence under low-temperature stress

The effects of incorporating 5-aminolevulenic acid (ALA) into the priming solution on low-temperature germination and emergence percentage performance of red pepper (Capsicum annuum cv. Sena) seeds before and after seed storage were investigated. Seeds were primed in 3% KNO₃ solution for 6 days at 25 °C in darkness containing 0 ppm, 1 ppm, 10 ppm, 25 ppm, 50 ppm or 100 ppm ALA. Following priming, seeds were either immediately subjected to germination and emergence tests at 15 °C or stored at 4 °C or 25 °C for 1 month after which they were subjected to germination and emergence tests at 15 °C. Priming pepper seeds in the presence of ALA improved final germination percentage (FGP) and germination rate (MGT) at 15 °C compared to non-primed seeds. The highest FGP was obtained from seeds primed in the presence of 25 ppm and higher ALA concentrations while the highest MGT was obtained from seeds primed in KNO₃ supplemented with 10 ppm ALA. Emergence percentages were the highest for the seeds primed in the presence of 25 ppm ALA and 50 ppm ALA while non-primed seeds had the lowest emergence percentage. Highest emergence rates (MET) and heaviest seedlings were also obtained from seeds primed in KNO₃ supplemented with 50 ppm ALA. Although all priming treatments improved germination and emergence performance of pepper seeds at 15 °C following 1 month of storage under two different temperatures, inclusion of 25 ppm and 50 ppm ALA into the priming solution resulted in higher germination and emergence percentages and faster germination and emergence compared to seeds primed in KNO₃ only and non-primed seeds. These results indicate that priming seeds in 25 ppm and 50 ppm ALA incorporated into the KNO₃ solution can be used as an effective method to improve low-temperature performance of red pepper seeds and that these seeds can be stored for 1 month at 4 °C or 25 °C and still exhibit improved germination and emergence performance at 15 °C.     

Fifteen years of observations on the agronomic behaviour of seven heat-treated pear tree cultivars

Performance of heat-treated clones of seven pear cultivars in a contaminated orchard were observed over 15 years and compared with non-treated clones (virus infected) of the same cultivars. The heat-treated clones were more successful in budding, had a 10% increase in vigour, 15–50% better cropping depending on the cultivar. The yield per tree size varied between the heat-treated and non-treated from 3 to 16 kg per tree per centimetre trunk girth. Only “Général Leclerc” proved an exception: the treatment seemed to have brought about the appearance of a “variant” which flowered later and had a smaller yield. Throughout the 15 year study period we did not observe any natural viral contamination in the orchard.     

台湾青枣不同品种花粉萌发和生活力测定

以5个台湾青枣品种盛花期花粉为试材，应用正交试验测定不同品种花粉萌发率及适宜的萌发条件，并用4种不同方法测定花粉生活力。结果表明：（1）不同品种的花粉萌发率存在显著差异，其中大世界的花粉萌发率最高。（2）硼酸浓度、培养温度等因素对花粉萌发率有极显著影响。最适培养基为含琼脂1％、蔗糖15％、硼酸0．02％的组合，适宜温度为30—32℃。（3）花粉生活力的测定中，离体萌发法是最佳选择，I—KI染色法、醋酸洋红染色法和TTC染色法不适宜用作台湾青枣花粉生活力的测定。     

Effect of postharvest desiccation at high temperature on soluble sugar changes of two supersweet sweet corn cultivars

The alteration in the soluble sugar contents of two commercial cultivars of sweet corn, Zea mays L. Supersweet Jubilee and Sweetie, desiccated at 60°C was determined. The loss of kernel moisture under field condition was gradual, but was rapid under laboratory condition at 60°C. Constant dry weight of kernels was reached after 24 h. In both cultivars, postharvest desiccation at 60°C significantly increased raffinose and fructose contents over those of non-desiccated control. Sucrose content of kernels, however, was significantly decreased by desiccation in both cultivars. In cv. Supersweet Jubilee, raffinose, sorbitol, fructose and glucose were significantly increased in kernels contained in plastic bags held at 60°C compared with naked desiccation at 60°C. In cv. Sweetie, however, only fructose and glucose contents were increased and not raffinose, sorbitol or sucrose. It was concluded that high temperature desiccation had a profound effect on sweet corn soluble sugars which may be associated with their cell membrane protecting role.     

Seed dormancy and germination of Michelia yunnanensis (Magnoliaceae)

Michelia yunnanensis Franch. is a Chinese endemic ornamental shrub with potential for greater utilization as a landscape and medicinal plant if propagation was less difficult. Seed development and breaking of seed dormancy were investigated to improve propagation of M. yunnanensis. No fresh seeds germinated when tested at the time of dispersal. Newly matured seeds of M. yunnanensis contained differentiated linear underdeveloped embryos that were physiologically dormant. The embryo/seed length ratio of M. yunnanensis was 0.15. Warm stratification did not break seed dormancy. Dormancy was broken by cold stratification at 4 °C but not by flowing water or nitrate. Embryos developed grew inside seeds during cold stratification at 4 °C. In newly harvested dormant seeds, embryos were 0.94 mm long and increased in length 139% before radicle emergence (germination). GA₃ substituted for cold stratification to break dormancy in seeds of M. yunnanensis incubated at 25 °C or 20/25 °C. Mature M. yunnanensis seeds exhibited intermediate complex morphophysiological dormancy. Optimal germination of non-dormant seed in terms of both germination percentage and rate occurred at 20/25 °C.     

The influence of arbuscular mycorrhizal colonisation on key growth parameters and fruit yield of pepper plants grown at high salinity

This study investigated the effects of arbuscular mycorrhizal (AM) colonisation by Glomus clarum on growth and fruit yield of pepper (Capsicum annum cv. 11B 14) grown at high salinity. The experiment was conducted in pots containing a mixture of perlite and sand (1:1, v/v) under glasshouse conditions. Treatments were: (1) no added NaCl without arbuscular mycorrhizae (NS-AM), (2) no added NaCl with arbuscular mycorrhizae (NS + AM), (3) added 50 mM NaCl without arbuscular mycorrhizae (S1-AM) and (4) added 100 mM NaCl without arbuscular mycorrhizae (S2-AM), (5) added 50 mM NaCl with arbuscular mycorrhizae (S1 + AM) and (4) added 100 mM NaCl with arbuscular mycorrhizae (S2 + AM). The NaCl treatments reduced pepper shoot and root dry matter, and fruit yield compared with the non-saline treatments. The concentrations of N, P and K, in the leaves were significantly reduced by salinity stress, however, mycorrhizal colonisation of the salt-stressed plants restored leaf nutrient concentrations to the levels in non-stressed plants in most cases. AM inoculation improved pepper growth under salt or saltless conditions and reduced cell membrane leakage.     

The effects of pre-sowing seed treatments on the germination and emergence of lettuce seeds at high salt concentrations

Radicle emergence in lettuce seeds cultivar ‘Hilde’ was reduced by NH₄NO₃ above 8×10^?2M, while radicle extension was inhibited by 8×10^?2M NH₄NO₃ and no seedlings emerged. Inhibition of radicle emergence by 8 and 16×10^?2M NH₄NO₃ was prevented by soaking seeds for 4 h before sowing in a mixture of $\text{GA}{}_{\mathrm{<mtext>4</mtext><mtext>7</mtext>}}$ and kinetin+phosphate buffer, and was partially prevented by soaking them for 4 h before sowing in phosphate buffer. These treatments did not prevent inhibition of radicle emergence by 32×10^?2M NH₄NO₃, but seeds soaked in growth regulators or phosphate buffer before sowing and taken from this NH₄NO₃ solution after 7 days and washed to remove excess salt gave 45–52% germination compared with 12 % for untreated seeds. Pre-treatment of the seeds did not prevent the inhibitory effect of NH₄NO₃ on radicle extension. In field experiments seeds treated with growth regulators + phosphate buffer or phosphate buffer alone gave a higher final percentage emergence from soils given 125 kg N/ha than did untreated seeds.     

Effects of pre-sowing seed treatments and temperatures on tomato seed germination and seedling emergence

Sowing pre-germinated seeds with radicles 2–3 mm long reduced the time from sowing to seedling emergence to 17 days compared with 41 days in untreated seeds at soil temperatures of 10°C, and to 5 days compared with 11 days at 18°C. Sowing pre-germinated seeds also improved percentage seedling emergence and reduced the variability of times of emergence of individual seedlings. Seeds imbibed for 56 h before sowing (radicles just emerging) emerged about 3 days earlier at both 10°C and 18°C than untreated seeds. Seeds soaked in a solution containing 1.5% each of KNO₃ and K₃PO₄ for 5 days at 24°C, or in “Carbowax 20 M” for 20 days at 15°C, and then dried before sowing, gave results similar to imbibed seeds. Soaking seeds in 70% of their weight of water followed by drying for different lengths of time and for different numbers of cycles of wetting and drying did not improve germination or seedling emergence.     

Agronomic characteristics and carotenoid content of five Bola-type paprika red pepper (Capsicum annuum L.) cultivars

The production of sweet paprika in Spain uses exclusively fruit of Bola-type Capsicum annuum L. This work describes the evaluation of the agronomic behaviour of five new cultivars of the Bola-type paprika red pepper, selected in the Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA), and grown in Extremadura for 3 years. The colour and the pigment content of the paprika elaborated following the traditional procedure of La Vera were also studied.     

Evaluation of crucial factors for implementing shed-microspore culture of Indonesian hot pepper (Capsicum annuum L.) cultivars

A shed-microspore culture protocol was developed in Wageningen for producing doubled haploid plants in several genotypes of Indonesian hot pepper (Capsicum annuum L.). For transfer of technology to Indonesia, three factors were studied that appeared crucial for successful implementation in practice. First, application in the culture medium of a combination of the antibiotics timentin and rifampicin at the concentrations of 200 and 10 mg/l, respectively, prevented bacterial contamination from the donor explants. Second, in vitro application of colchicine (100 μM) during the first week of culture was highly effective in increasing the percentage of doubled haploid plants. Third, a comparative analysis of the ploidy level of plants regenerated from shed-microspore-derived embryos using chloroplast counts in guard cells of leaf stomata and flow cytometric measurement of leaf nuclear DNA content, revealed that the first procedure is a reliable and an easy to use method for ploidy determination with hot pepper.