Removal of flowers or inflorescences affects ‘Barnea’ olive fruitlet post-anthesis abscission

A typical olive (Olea europaea L.) inflorescence consists of about 20 flowers. However, in many cultivars, only one fruit develops. This is due to massive abscission of flowers and fruitlets, which occurs during the first month after anthesis. In this study, we used the olive cultivar 'Barnea' to characterize the abscission mechanism and to try to increase fruit set by increasing the number of developed fruit per inflorescence. Removing the lateral flowers 3 weeks before anthesis increased fruit set by more than 50%. Removing all inflorescences but one from a branch increased the number of developed fruits from 0.93 to 2.8 during 2017 and from 0.91 to 3.34 fruits per inflorescence in 2018. Sugar quantification in the pistil revealed that starch level is high on the day of anthesis and low 25 days later in abscised as well as in developed fruit. Soluble carbohydrates are low on the day of anthesis, low in abscised flowers/fruitlets 25 days after anthesis and high in developed fruit. Screening the natural variation found in the Israeli germplasm collection revealed that in most cultivars less than one fruit per inflorescence has developed. However, there are unique cultivars with a higher fruit set.     

喷施乙烯利对‘HAES900’澳洲坚果果实脱落和品质的影响

为解决澳洲坚果采收难和采收成本高的关键问题,以‘HAES900’澳洲坚果成龄结果树为材料,在采收期分别喷施低浓度梯度(0.40、0.65、0.90 g/L)和高浓度梯度(0.80、1.30、1.80 g/L)的乙烯利溶液,对喷施乙烯利溶液后的落果率、果柄附着力和果实品质进行了调查和分析。结果表明,低浓度乙烯利对果实脱落有促进作用,但落果率达不到生产要求;喷施1.80 g/L的乙烯利溶液2周和4周后的落果率分别达到98.75%和100.00%,可满足生产要求;喷施浓度为0.80、1.30和1.80 g/L的乙烯利会使果柄附着力显著降低,且果柄附着力与落果率呈极显著负相关;果柄附着力可作为判断澳洲坚果适宜采收期的指标之一。采用本方法采收对壳果含水量、单壳果重、壳果平均横径、单果仁重、出仁率和一级果仁率等品质参数无显著影响,且可缩短澳洲坚果采收周期,降低采收成本。     

不同灌溉方式对农田土壤性状和花生落果率的影响

于2014―2015年度麦茬花生生长季,设置移动式管灌、微喷带灌溉和不灌溉3种处理,研究了不同灌溉方式下农田土壤体积质量、土壤孔隙度、水稳定性土壤团聚体组成、花生产量和花生落果率的变化。结果表明,与移动式管灌处理相比,微喷带灌溉处理的土壤体积质量、粒径小于0.25 mm水稳定性土壤团聚体数量和花生落果率分别降低了7.6%、6.4%和66.8%,土壤孔隙度增加了8.4%,而2处理间花生产量没有显著差异。综合考虑花生产量,土壤物理性状和花生落果率的变化,微喷带灌溉是试验条件下能够降低花生收获难度的灌溉方式。     

The Relationship Between Sugar-Nitrogen Ratio and Reproductive Organs Abscission in Faba Bean (Vicia Faba L.)

The changes of soluble sugar and total nitrogen content of vegetative organs in faba bean, sugar-nitrogen ratio, abscission of reproductive organs and the relationship between sugar-nitrogen ratio and abscission probability were studied using the faba bean cultivar Xichang Dabai . Plants were field grown in 1986, 1988 and 1990. The lands were separated into high yield land, middling yield land and low yield land according to grain yield at maturing stage. The soluble sugar content in vegetative organs (leaf + stem) was greatest from branching to floral initiation stages and pod-set to filling grain stages, and distinctly decreased at the onset of bloom and maturing stages. The total N content was greatest at branching stage, and gradually decreased with growth. In general, the sugar and total N contents in high yield lands were greatest, followed by that in middling yield and low yield lands. The sugar-nitrogen ratio varied depending on the soluble sugar content.
Average yield on high yield lands, middling yield land and low yield land across 3 years were 5048.77 kg/ha, 3744.01 kg/ha and 2378.22 kg/ha, respectively. The total reproductive organs abscission exceeded 90 % of total flower buds. Abscission probability averaged across 3 yield lands and 3 years were 21.6 %, 84.0 % and 32.8 % in flower buds, flowers, and pods, respectively. Node 7–12 of canopy produced more flowers, and fewer flowers and pods were produced in the upper and lower regions. Photosynthate supply has been implicated in control of abscission. Faba bean reproductive organs abscission probability increased with the sugar-nitrogen ratio of vegetative organs decreasing. It seemed that the soluble sugar content influenced significantly the shedding rate during flowering and pod-growing stages.     

棉花早期热激处理与高温期蕾铃脱落关系的初步研究

研究了棉花早期热激处理与高温期蕾铃脱落的关系，结果表明：早期热激处理有助于高温期棉株体内产生更丰富的热激蛋白，从而提高棉株的耐热程度，降低脱落率达１．７～３．０个百分点。但不同的品种，早期热激处理的最适生长阶段不同品种有差异     

棉花热激蛋白(HSP)的研究及其应用前景展望

本文简要介绍了热激蛋白（ＨＳＰ）在作物中的研究概况；棉花ＨＳＰ产生的规律性及其与高温期蕾铃脱落关系的初步研究结果；并展望了ＨＳＰ在棉花等喜温作物高产栽培与育种中的应用前景     

不同长绒棉品种的蕾铃脱落规律及影响因素

对南疆6个长绒棉品种新海7号、新海3号、新海14号、新海16号、新海20号和新海21号的蕾铃脱落规律的系统调查研究表明:长绒棉蕾铃脱落率高于50;,落铃率高于落蕾率,品种之间差异明显,新海14号脱落率最高,达到65;以上.蕾铃脱落的峰期出现在7月下旬,而且蕾铃脱落率的变化趋势与7月中下旬最高气温的变化规律基本一致.6个品种不同果枝之间的脱落率变化规律相似,上部果枝蕾铃脱落率高于中下部果枝,主要是因为上部果枝的落蕾率显著的高于中下部果枝,新海16号甚至高出了35个百分点.除了新海3号和新海16号中部结铃数高于两端以外,其余4个品种结铃数皆是下部＞中部＞上部,即通常指的"中空"现象.从产量上看,蕾铃脱落率高的品种其最终产量偏低,相反蕾铃脱落率低的品种,最终其产量也高,总体来讲新海7号＞新海20号＞新海3号＞新海21号＞新海16号＞新海14号.     

棉花蕾铃生长发育和脱落的模拟研究

采用车箱理论方法,根据棉花生长发育过程中光合产物的源、库、流关系和供需平衡,定量模拟了不同品种、播期棉花蕾铃发育和脱落动态。结果显示,棉花单株蕾数、成铃数、吐絮铃数的模拟值与观察值之间的RMSE分别平均为3.36、1.57和1.04（个）;单铃重的RMSE为0.15 g;脱落率的RMSE为8.15%。表明应用本系统模拟蕾铃发育和脱落     

禾本科植物落粒机理研究进展

落粒性是野生植物为有效繁衍后代、扩大种群而形成的一种适应特性,但对种子生产可造成不利影响。离区的形成、发育和降解是植物落粒的直接原因,植物激素产生促进或抑制脱落的信号,细胞壁水解酶可引起离区细胞的降解,这些过程的发生受多个基因调控,且调控网络复杂。对于种子落粒的相关研究已在水稻、小麦等农作物中深入开展,而牧草领域则相对较少。综述禾本科植物落粒研究的最新进展,以期为禾本科牧草落粒机理深入挖掘以及品种选育提供理论参考。     

Nutrient composition and short-term release from <Emphasis Type="Italic">Croton macrostachyus</Emphasis> Del. and <Emphasis Type="Italic">Millettia ferruginea</Emphasis> (Hochst.) Baker leaves

A field study was conducted to investigate the nutrient content of green and abscised leaves of Croton macrostachyus Del. and Millettia ferruginea (Hochst.) Baker and their decomposition to return these nutrients to the soil in the short-term. Green and abscised leaves were collected from trees of comparable size in Wondo Genet, Ethiopia, and were incorporated into litterbags to decompose for a period of 12 weeks. Green leaves of C. macrostachyus had significantly higher nutrient concentrations than those of M. ferruginea. In both species, green leaves had significantly higher (P<0.05) C, N and P and significantly lower (P<0.05) lignin and polyphenol concentrations than abscised leaves. Fifty percent of the biomass applied was lost during the first 7 weeks in C. macrostachyus, which was about 3 times faster than that of M. ferruginea. The half-lives of N and P were 5–8 weeks and 4–6 weeks, respectively, in C. macrostachyus; the corresponding values for M. ferruginea were 6–8 and about 22 weeks, respectively. Only 15.7% and 26.8% of green and abscised leaves of C. macrostachyus, respectively, were recovered after the 12 weeks of decomposition. The corresponding values were about 3.5-fold and 2.5-fold higher for M. ferruginea. Generally, leaves with higher initial lignin, polyphenol, lignin:N and C:N ratios had lower decomposition and mineralization rates. In both species, removal of leaf biomass before abscission (e.g. by pruning) could enhance both the quantity and rate of nutrient return to the soil.