Allelopathic potential of wild onion (Asphodelus tenuifolius) on the germination and seedling growth of chickpea (Cicer arietinum)

Water extracts obtained from the roots, shoots, and fruits of mature wild onion ( Asphodelus tenuifolius ) plants and soil taken from an A. tenuifolius field were used to determine their allelopathic effects on the germination and seedling growth of chickpea ( Cicer arietinum ) in the laboratory. The roots, shoots, and fruits of A. tenuifolius were soaked individually in water in a ratio of 1:20 (w/v) for 24 h to prepare the extracts. Distilled water was used as the control. The germinated seeds were taken out from the Petri dishes and counted every day for 12 days. The seeds of chickpea were also sown in sand and in each of the controlled, normal soil and the soil taken from the A. tenuifolius -infested field in Petri dishes to record the length and weight of the roots and shoots 18 days after sowing. The mean germination time reached the maximum amount for the stem and fruit extracts. The fruit extract caused the most reduction in the germination index and the germination percentage of chickpea. The different wild onion organ extracts significantly reduced the root and shoot length and biomass of the chickpea seedlings compared with the distilled water. The fruit extract of wild onion proved to be the most detrimental to the root length, shoot length, and dry weight of the chickpea seedlings. The soil beneath the A. tenuifolius plants significantly reduced the emergence, root length, shoot length, shoot dry weight, and seedling dry weight but increased the root dry weight of the chickpea seedlings. It is suggested that A. tenuifolius releases phytotoxic compound(s).     

多元醇络合硼对油菜苗期生长及生理特性的影响

以油菜品种Cao221167为试验材料,采用水培方法,研究山梨醇(S)、山梨醇-硼(SB)、甘露醇(M)、甘露醇-硼(MB)、丙三醇(G)、丙三醇-硼(GB)、硼酸(BA)、缺硼(B0)等不同硼处理对油菜农艺性状、根系活力、色素含量以及各部位硼的吸收分布的影响。结果表明:仅添加有机多元醇处理(S、M和G)的油菜幼苗各项形态和生理特性(株高、地上部干鲜质量、色素含量和根系活力)与缺硼处理无差异,而有机多元醇和硼酸络合后各指标均提高,说明有机多元醇与硼酸形成的有机多元醇络合硼对油菜幼苗生长起促进作用。有机多元醇络合硼处理(SB、MB和GB)和硼酸处理比较表明,有机多元醇络合硼和硼酸均能促进植株生长,但有机多元醇络合硼对油菜幼苗生长以及生理特性的营养作用更显著;其中,甘露醇-硼处理促进油菜幼苗干鲜质量的提高,总干鲜质量较硼酸处理分别增加40.56%和17.29%;不同有机多元醇络合硼处理和硼酸处理的油菜各部位钾、钙、镁等元素含量均高于缺硼处理;丙三醇-硼处理比硼酸处理显著提高油菜叶片色素含量、根系活力以及地上部硼含量。     

Irrigation water reduction using System of Rice Intensification compared with conventional cultivation methods in Iraq

A field study was conducted at Al-Mishkhab Rice Research Station (MRRS) during the summer season 2009 to evaluate irrigation water use efficiency (IWUE) using Anbar 33 variety with the System of Rice Intensification compared to traditional methods. During the growth phase, the number of leaves, stems, and roots, and the average plant height were measured every 15 days for the two sets of methods. At maturity, the depth and length of plant roots was assessed, along with leaf area index (LAI) of the flag leaf and plant height. The amount of irrigation water applied was measured by water meter for both methods. SRI principles for plant age, spacing, etc., were implemented in the SRI plots. The results indicated more vigorous growth of roots under SRI methods, reaching 13,004 cm plant⁻¹ compared with non-SRI results of 4,722 cm plant⁻¹. There was 42% increase in grain yield when SRI methods were used. These had water use efficiency (WUE) of 0.291 kg m⁻² compared with WUE of 0.108 kg m⁻² for non-SRI cultivation, almost a threefold difference. SRI practices reduced the need for irrigation water by 38.5%.     

Assessment of Environment-friendly Usage of Spent Wash and its Nutritional Potential for Sugarcane Production

Excessive and inappropriate use of fertilizers is a key factor of low sugarcane yield and degradation of soil. A two-year (2013–14 and 2014–15) field study was conducted to assess the impact of combined application of organic and inorganic fertilizers on sugarcane at research farm of Shakarganj Sugar Research Institute, Jhang, Pakistan. Experiment was conducted under randomized complete block design with three replications. Treatments were used as control (no exogenous application), spent wash (160 t ha^?1), (nitrogen, phosphorus and potassium) NPK (168:112:112 kg ha^?1), spent wash (120 t ha^?1) + NPK (42:28:28 kg ha^?1), spent wash (80 t ha^?1) + NPK (84:56:56 kg ha^?1), spent wash (40 t ha^?1) + NPK (126:84:84 kg ha^?1), and spent wash (160 t ha^?1) + NPK (42:28:28 kg ha^?1). Application of spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1 resulted maximum crop growth rate (11.35 g m^?2 d^?1), leaf area index (7.78), and net assimilation rate (2.53 g m^?2 d^?1). Maximum number of millable canes (14), weight per stripped cane (0.90 kg), stripped cane yield (117.60 t ha^?1) and unstripped cane yield (141.25 t ha^?1) were observed with spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1, followed by sole fertilizer application @ 168:112:112 kg NPK ha^?1 and spent wash @160 t ha^?1 + NPK @ 42:28:28 kg ha^?1. Similar trend was observed regarding quality parameters. The maximum benefit–cost ratio (1.80) was achieved with integrated application of spent wash @ 80 t ha^?1 + NPK @ 84:56:56 kg ha^?1.     

四川地区玉米/大豆带状套作对大豆形态、叶绿素荧光特征及系统产量的影响

玉米/大豆带状套作可以充分利用光环境,提高单位土地面积物质产出。为探明玉米/大豆带状复合种植模式下不同空间配置对大豆冠层光环境、形态、产量及系统效益的影响,进而为大豆高产优质栽培提供依据,本研究选用半紧凑型（‘川单418’）和紧凑型（‘荣玉1210’）玉米品种与大豆带状套作,固定带宽为200 cm,玉米采用宽窄行种植,玉米窄行距设置3个处理：20 cm、40 cm、60 cm;并以单作大豆（SS）作为对照。分析透光率、形态、光合色素、荧光参数、生物量和系统产量的变化规律。结果表明：套作大豆冠层透光率、红光/远红光（R/FR）比值随玉米窄行距的增大而逐渐降低;套作下大豆茎粗、节数、茎干重和全叶干重均随玉米窄行距增大呈降低趋势,最大值出现在玉米窄行距20 cm处理下;与单作大豆相比,两个玉米品种下大豆茎粗、节数、茎干重和全叶干重均显著降低,而第2节间长和主茎长显著升高。套作下大豆叶片光合色素含量随玉米窄行距的增大而逐渐降低,各行距处理及不同玉米品种下套作的叶片光合色素含量均低于单作大豆。大豆叶片荧光参数F_v/F_m、NPQ、F_q''F_m''和F_q''/F_v''随玉米窄行距的增大均呈先增大后减小的趋势,而F_o变化趋势与之相反。玉米收获后,大豆光环境得到改善并迅速恢复生长,套作大豆形态生理指标与单作差异减小,但由于前期玉米的遮荫,各套作处理间大豆产量差异仍显著。通过系统效益分析,在玉米窄行距40 cm处理下,套作系统综合产量最高,两玉米品种下玉米、大豆产量平均分别为8 559.52 kg·hm^-2、1 717.60 kg·hm^-2,土地当量比平均达1.57。本试验中大豆与两个株型玉米套作,大豆形态生理指标差异影响不显著。因此,选择紧凑或半紧凑玉米品种,适度缩小玉米窄行距可以显著改善带状套作大豆的生长环境,提高其生物量和产量。     

番茄黄色柱头突变体ys的表型与遗传规律分析

通过EMS诱变获得了1个可稳定遗传的番茄黄色柱头突变体,命名为ys(yellow stigma)。色素含量测定发现:同野生型相比,突变体ys柱头中的叶绿素和类胡萝卜素含量没有明显变化,但对香豆酸和柚皮素查尔酮含量显著高于野生型,推测呈黄色的柚皮素查尔酮的大量积累可能在黄色柱头形成过程中起着重要作用。此外,分析发现,突变体和野生型在柱头表面结构、柱头可授性及花粉活力方面没有显著差异。对突变体ys与野生型构建的F_1、F_2、BC_1以及BC_2群体的遗传分析发现,F_1和BC_2均为绿色柱头植株,F_2和BC_1群体绿色柱头植株与黄色柱头植株的比例符合3∶1和1∶1的分离比(P0.05),表明黄色柱头突变受1对隐性基因控制,其遗传方式符合孟德尔遗传定律。     

Allelopathic potential of Acacia melanoxylon on the germination and root growth of native species

Water extracts that were obtained from the flowers and phyllodes of Acacia melanoxylon were used to determine their allelopathic potential in relation to the germination and seedling growth of the native species, cocksfoot (Dactylis glomerata), perennial ryegrass (Lolium perenne), and common sorrel (Rumex acetosa), as well as a general biotest specie, lettuce (Lactuca sativa), in laboratory bioassays. The flowers and phyllodes of A. melanoxylon were soaked separately in distilled water in a ratio of 1:1 (w/v) for 24 h in order to prepare the aqueous extracts. Distilled water was used as the control. The seeds of the target species were germinated in Petri dishes and counted daily for up to 7 days. The A. melanoxylon flower extract (100%, 75%, and 50%) decreased the seed germination of D. glomerata, R. acetosa, L. perenne, and L. sativa. The flower extract caused the most reduction in the germination index and germination speed in D. glomerata, L. perenne, and L. sativa. The mean LC₅₀ value of the A. melanoxylon flower and phyllode extracts in relation to the germination inhibition of L. perenne was 43% and 41%, respectively, 40% and 38%, respectively, in R. acetosa, and 53% and 41%, respectively, in L. sativa. All four concentrations of the flower extract proved to be more phytotoxic than the phyllode extract, reducing the root length of all four species, while the phyllode extract decreased the root length of L. perenne and R. acetosa at the 100% concentration. The L. perenne and D. glomerata grass seeds were more sensitive regarding germination, as compared to L. sativa and R. acetosa. The flower aqueous extract of A. melanoxylon was more phytotoxic, as compared to the phyllode aqueous extract, even at the lowest concentration (25%).     

生防菌对向日葵列当的防除作用的初步研究

通过室内穴盘和连续两年遮雨棚盆栽试验,研究放线菌淡紫褐链霉菌(Streptomyces enissocaesilis,509),真菌灰黄青霉(Penicillium griseofulvum,CF3)和放线菌密旋链霉菌(Streptomyces pactum,Act12)3种生防菌对寄主植物向日葵的促生作用和对向日葵列当种子萌发的抑制作用。结果表明:1)CF3和Act12处理条件下,列当的出土数和寄生总数量显著降低,在新葵6号中CF3抑制列当寄生率高达74.4%,Act12抑制列当寄生率为68.7%,509抑制列当寄生率为53.0%;2)在列当寄生胁迫下,生防菌处理向日葵相比对照生物量有显著的增高,根冠比显著增大,含水量显著升高,生防菌处理的向日葵地上部和根的含水量≥70%。本研究表明CF3和Act12具有作为防除向日葵列当优良生防菌种的可能性。