胡椒竹片法快速繁殖技术研究

竹片法胡椒快速繁殖技术的试验表明,以椰糠、土、沙(体积比为1∶1∶1)为扦插基质的成活率最高,达100%;以椰糠和沙(1∶1)作为竹片内填充的生根基质,茎蔓生长快,平均生长速度1.0cm/d繁殖产生的单节插条苗的平均根数、平均根长、平均节间长分别为8条、4.0 cm、6.3 cm。竹片繁殖技术是一种成功的胡椒种苗快速繁殖技术。     

陕西省油松良种基地生产能力分析

对陕西省己建成的油松良种基地现实良种生产数量和质量分析结果表明,良种的遗传品质和播种品质基本上达到了营建初级种子园的目的,但基地生产能力较低,良种数量远远满足不了造林用种的需要。并对加强良种基地管理,提高良种生产能力提出了一些看法。     

糖种类和浓度及pH值对长白山笃斯越桔组培苗增殖和生根的影响

以长白山笃斯越桔组培苗为试材,研究糖及pH值对笃斯越桔组培苗继代增殖及生根的影响,结果表明,30g/L的蔗糖浓度适宜于继代和生根,继代培养30d后的增殖倍数可达5.7倍,生根培养50d后的生根率可达80%;pH值4.2的培养基适宜笃斯越桔继代增殖及生根,继代培养30d后的增殖倍数可达5.9倍,生根培养50d后的生根率可达80%。     

马铃薯脱毒种薯的快速繁殖技术

马铃薯退化现象是由于感染一种或多种过滤性病毒引起的,它是影响高产稳产的主要因素。病毒不仅赖于植物体内部生存,并且参加和改变植物体内许多代谢途径的生理活动。当被不同病毒侵染的马铃薯出现各式各样症状,就是病毒在植物体内部干扰机体代谢作用的结果,所以只有从内部清除病毒,获得脱毒健康种薯,才是治本的办法。     

香椿的试管繁殖技术

选取当年生半木质化、具腋芽的香椿茎段作为外植体,诱导腋芽萌发,进行芽苗增殖和生根培养。通过试验,筛选出了各阶段适宜的培养基组成及试管苗移栽条件。结果表明,香椿萌芽诱导中,M S基本培养基效果优于1/2M S;芽增殖阶段,适宜的培养基是M S 6-BA 0.2 m g/L GA32.0,有效增殖倍数为3.38;在1/2M S 1.0 m g/L IBA中,试管苗生根率最高,可达69%;适宜的移栽时间是3~7月初,移栽基质以蛭石或和沙为好。     

Rapid in vitro propagation of Dendrobium hybrids through direct shoot formation from foliar explants,and protocorm-like bodies

In vitro propagation protocol for Dendrobium hybrids Sonia 17 and 28, two highly priced commercial cut flower cultivars through direct organogenesis from in vitro derived foliar explants was established. Rapid clonal propagation was achieved by subsequent induction of protocorm-like bodies (PLBs) and its conversion to shoots. No significant differences were observed in the induction of direct shoots, shoot multiplication, PLBs formation and subsequent shoot development and rooting of shoots between the two cultivars. Leaf explants from flower stalk node derived shoots cultured on half-strength Murashige and Skoog (MS) medium supplemented with 44.4 μM N⁶-benzyladenine (BA) developed more than seven shoots per explant. The isolated shoots transferred onto the same medium induced more than eight PLBs from the base within 60 days, which upon transferral to fresh medium having the same level of BA facilitated rapid proliferation. More than 200 PLBs were yielded from fifth subculture. Half-strength MS medium containing 6.97 μM kinetin (Kn) facilitated conversion of more than 90% PLBs to shoots. PLBs exhibited proliferation without decline up to the 15th subculture. Half-strength MS medium with 2 g l⁻¹ activated charcoal was the best for in vitro rooting. Plantlets of the hybrids exhibited more than 80% ex vitro establishment.     

植物激素在离体培养苦楝中对芽及嫩梢的增殖效应

本文研究了10年生苦楝返幼茎段离体培养中植物激素对芽及嫩梢的增殖效应。方差分析表明,BAP决定了每个外植体上的芽数,而NAA决定了丛芽率(%)。对于芽增殖,最佳BAP:KT为1:1。对于有效嫩梢增殖,细胞分裂素和生长素之间具有极显著的交互效应。细胞分裂素的作用大于生长素,而BAP的作用大于KT,NAA的作用大于IBA。芽及有效嫩梢增殖最佳的激素组合为BAP0.5ppm NAA0.005ppm,BAP:NAA的最佳比例为100:1。     

Quantifying and Modelling the Mobilisation of Inoculum from Diseased Leaves and Infected Defoliated Tissues in Epidemics of Angular Leaf Spot of Bean

Daily multiplication factor (number of daughter lesions per mother lesion per day) values were experimentally measured in four replications of a monocyclic experiment on angular leaf spot (ALS) of bean, where sources of inoculum were artificially established within a bean canopy, on the ground (defoliated infected leaves), or both. Daily multiplication factor of lesions in the canopy (DMFRc) was higher than that of infectious, defoliated tissues (DMFRd) in all replications. Both DMFRc and DMFRd were strongly reduced under dry compared to rainy conditions. Under rainy conditions for spore dispersal DMFRd was about two to three times smaller than DMFRc. Defoliated leaves may nevertheless represent a significant source of infection, depending on the amount of infectious tissues. Mother lesions within the canopy generated more daughter lesions in the medium (or lower) layers of the canopy than at its upper level (DMFRc higher at the medium and lower layers of a canopy), whereas DMFRd values seemed to decrease with height in the canopy. A mechanistic simulation model that combines host growth and disease-induced defoliation was designed to simulate the respective contributions of the two components of the dual inoculum source of a diseased canopy (infected foliage and defoliated infectious tissues), and varying infectious periods in both sources. Simulations suggest that higher DMFRc values have a large polycyclic effect on epidemics whereas that of DMFRd is small, and that large effects of the infectious period of lesions in the canopy are found when DMFRc is high. Simulations using experimentally measured DMFRc and DMFRd values indicated much stronger epidemics in rainy compared to dry conditions for spore dispersal, but disease persistence in the latter. The implications of considering a dual source of inoculum in the course of a polycyclic process are discussed with respect to epidemic thresholds.     

Propagation of potato by shoot tip culture in petri dishes

Summary A method is described for propagating potato shoot tips with liquid culture in petri dishes. With cv: Exton, Pontiac, Kennebec and Sebago multiplication rates could exceed 8-fold every 8 weeks. The petri dishes can be packed so as to accommodate large numbers of multiplying tips in a small space.