Mass propagation of Satyrium nepalense D.Don.—A medicinal orchid via seed culture

An in vitro plant regeneration protocol was successfully established in Satyrium nepalense, a terrestrial orchid by culturing immature seeds from unripe fruits. Seeds were germinated on Murashige and Skoog, Knudson C and Knudson C modified Morel medium. The germination of the seeds and development of protocorm was highest in MS medium (86.7%) followed by Knudson C modified Morel medium (74%) and Knudson C medium (61.2%). Among the cytokinins tried for multiple shoot induction from the protocorm, 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ) was found to be superior. Indole-3-butyric acid (IBA) was effective for inducing healthy roots. Well-developed plantlets were hardened in vermicompost (leaf litter + cow dung 1:1), sand and coconut husk (1:1:1).     

Effect of set-size and storage temperature on bolting,bulbing and seed yield in two onion cultivars

The effects of three set-sizes (12.5, 17.5 and 22.5 mm in diameter) and seven storage temperatures (0, 5, 10, 15, 20, 25 and 30 °C) on bolting, bulbing and seed yield in two onion (Allium cepa L.) cultivars ‘Hygro’ and ‘Delta’ were investigated. The incidence of bolting increased linearly with set-size and curvi-linearly with decreasing storage temperature. Time to inflorescence emergence and floret opening showed a curvi-linear response to storage temperature with the earliest inflorescence emergence and floret opening occurring at 5 °C and the latest at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’. Seed yield per umbel also showed a curvi-linear response to storage temperature with the lowest seed yield occurring at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’ and the highest seed yield at 5 °C. For a seed crop, storage of large sets (22.5 mm) of these cultivars at 5 °C for 120 days appeared to be optimum with 5–12% higher seed yield per umbel than that of 90 days storage. Bulb yield showed a curvi-linear response to storage temperature with the highest bulb yield occurring at 25 °C and the lowest at 5 °C.     

脱落酸与种皮对杜梨种子休眠与萌发的影响

以当年新采收杜梨种子和自然贮藏1 a种子为试验材料,研究了种皮和不同浓度的脱落酸(ABA)对诱导杜梨种子休眠与萌发的影响.结果表明:杜梨种皮和脱落酸均能够抑制杜梨种子的萌发,种皮的抑制萌发效应显著大于ABA的作用,杜梨种子去除种皮后,休眠性可被部分解除.脱落酸对杜梨种子抑制萌发的效应在去皮和不去皮种子中表现明显差异,5 mg/L ABA浓度对未去皮种子产生明显抑制效应,20 mg/L ABA浓度对去皮种子产生明显抑制效应,说明未去皮种子对ABA的敏感性大于去皮种子.种皮与ABA的双重抑制效应,使种子对ABA浓度水平差异的敏感性增强.不同激素组合试验说明了GA3、6-BA和ABA在杜梨种子休眠与萌发中的作用.     

遮荫处理对侧柏种子萌发的影响

在不同光照梯度55.44%自然全光照(Natural sonlight,NS)、21.12%NS、3.47%NS 和0.86%NS的人工遮荫条件下,研究了侧柏(Platycladus orientalis)种子萌发的特点.结果表明:4个光照梯度处理的侧柏种子的萌发率分别为68.9%、82.2%、44.4%和42.2%;随着光照强度的减弱,种子萌发进程减慢;萌发指数和幼苗活力指数均在21.12%NS处理最大,分别为1.89和770.8.     

甜叶菊种子高效生产技术

根据生产实际,总结出甜叶菊种子高效生产技术。     

Application of crop growth simulation and mathematical modeling to supply chain management in the Thai sugar industry

The poorly integrated cane supply planning between mills and cane growers in the Northeast of Thailand generates an excess of cane supplies that exceeds the mills’ capacity during the peak of harvest season. Each grower individually determines his/her cultivation plan by selecting planting dates and cultivars based on one’s own preference without taking into account the individual mill’s capacity and other growers’ plans. This situation causes most sugarcane grown in this area to reach its mature stage at the same period. In this study, we propose a framework of cultivation planning to cope with the problem. The focus of the cultivation plan is a long-term plan to determine the cultivation time, the cultivar selection and the corresponding prospective harvesting time window for each field such that overall sugar production is optimized.The crop growth model and a mathematical model are employed for yield simulation and optimization task. The crop growth model enables decision-makers to visualize cane production of each individual field at different dates with different cultivars and allow decision-makers to apply the mathematical programming to cultivation planning. The suggested framework has the potential to increase sugar production by 23% when compared to the traditional method.     

Seed yield and water use efficiency of canola (Brassica napus L.) as affected by high temperature stress and supplemental irrigation

The effects of high temperature stress and supplemental irrigation on seed yield and water use efficiency (WUE) of canola (Brassica napus L.) were studied in a field experiment conducted for 2 years. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad, Iran. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of canola (Hyola401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 9 November, 6 December, 5 January, 4 February and 6 March in 2005-2006 and 6 November, 6 December, 5 January, 4 February and 6 March in 2006-2007, to have a wide range of environmental conditions around flowering and seed filling periods, and to coincide reproductive stages of the crop with high temperature stress. Seed yield was improved due to field management practices, such as supplemental irrigation and optimum sowing date. Supplemental irrigation was an efficient practice to mitigate water stress, and to increase aboveground dry matter and seed yield. There was a strongly negative relationship between seed yield and air temperature during reproductive stages. Delay in sowing led to more rapid developmental of canola, decreased aboveground dry matter, leaf area index (LAI), harvest index (HI), WUE, and seed yield. Achieving a high aboveground dry matter was an essential prerequisite for high reproductive growth and a high seed yield. Greater seed yield and WUE at first sowing date were associated with greater LAI and aboveground dry matter, and lower temperatures during reproductive stages. The results support the view that WUE can be used as an indirect selection criterion for seed yield in genotypic selection.     

斯卑尔脱细胞质对小麦种子长度、重量及杂种优势的遗传效应

为了筛选优良的新型小麦雄性不育系，对斯卑尔脱、云南铁壳麦、提莫非维小麦、拟斯卑尔脱山羊草等四种异源细胞质在同核异质条件下对不育系及其杂种一代的种子长度、重量及杂种优势的遗传效应作了比较研究。结果表明，斯卑尔脱细胞质对小麦种子大小、重量具有明显正效应，且筛选出了两个由其所配制的具明显杂种优势的杂交组合。这说明，斯卑尔脱细胞质不育系在栽培小麦中易于找到恢复源且恢复度高，其对种子大小和重量的稳定的正效应可能是产生较强杂种优势组合的重要原因之一。     

夏大豆籽粒成熟期根叶衰老特性的研究

以在冀中南地区夏播表现相对高产和低产的6个大豆品种为材料,通过测定鼓粒始期至成熟期根系和叶片的生理性状,探讨了大豆籽粒成熟期根、叶衰老之间的关系。结果表明:根、叶生理参数之间高度相关,不同产量类型大豆品种根系可溶蛋白含量、可溶糖含量、SOD活性衰退幅度均小于叶片,表明在生育后期叶片衰老先于根系;不同产量类型间比较,相对高产品种较相对低产品种根、叶各生理指标衰退速率慢,相对高产品种根系较叶片衰老的进程显著落后于相对低产品种。应在栽培上重视养根护叶及育种中加强根系生理性状的选择,延缓衰老进程进而获得高产。     

不同水稻种衣剂效果对比试验研究

通过对市场上常见的几种种衣剂进行对比试验,结果表明,使用种衣剂包衣对种子发芽、长势、病害防治均有很好的效果,优于常规处理,其中稻吉吉种衣剂处理的发芽势和发芽率均优于对照和常规处理,发芽势和发芽率分别可达到98%和96.5%;秧苗素质方面稻吉吉种衣剂处理各项指标均表现最高,其中干物质积累和茎基宽量分别高31.58%和16.3%。