Irrigation erosion of irrigated soils in the foothills of southern Kazakhstan

This paper presented the results from the study of irrigation erosion of irrigated lands in southern Kazakhstan. The main purpose of the work is the conservation of the fertility of irrigated soils, and then the soils of the upper, middle and lower sections of the slopes at the experimental site were studied. Based on field investigations, authors studied the water resistance of aggregates of gray-brown soils and light gray soils before and after irrigation and qualitative indicators of changes in physical and chemical properties of structured soils in irrigation were determined by conventional methods of soil research. The results indicated that the changes in the physical properties of soils by using polymeric compounds created a fundamentally new opportunity to control water erosion of soils.     

新疆五种猪毛菜属植物花粉形态研究

利用扫描电子显微镜对猪毛菜属3组5种植物的花粉形态进行了观察研究和比较分析,结果表明,所观察的5种植物的花粉形态相似程度很高,其形态均为球形,以单粒形式存在,萌发孔数量为18～38个,孔圆形或近圆形,均匀分布,外壁纹饰为不同形状的突起.种间花粉形态区别于花粉粒的大小,萌发孔的数量,花粉外壁纹饰的类型及突起密度.同时,研究从孢粉学角度初步分析了该属植物的系统演化关系,孢粉学特征揭示的系统演化关系与前人基于外部形态特征建立的猪毛菜属分组演化系统相一致,此外,还对五种植物的花粉萌发孔数量与其系统进化地位的关系进行了初步的探讨.     

Saline soil enzyme activities of four plant communities in Sangong River basin of Xinjiang,China

Soil enzyme activity plays an important role in the conversion of soil organic carbon into inorganic carbon,which is significant for the global carbon cycle.In this study,we investigated the soil enzyme activities of two ligninolytic enzymes(peroxidase and polyphenol oxidase)and five non-ligninolytic enzymes(α-1,4-glucosidase(AG);β-1,4-glucosidase(BG);N-acetyl-β-glucosaminidase(NAG);β-D-cellobiosidase(CBH);andβ-xylosidase(BXYL))in four plant communities of the Sangong River basin in Fukang,North Xinjiang,China.The four typical plant communities were dominated by Haloxylon ammodendron,Reaumuria soongonica,Salsola passerina,and Tamarix rarmosissima,respectively,with saline soils of varied alkalinity.The results showed that the soil peroxidase activity decreased seasonally.The activities of the five non-ligninolytic enzymes decreased with increasing soil depths,while those of the two ligninolytic enzymes did not show such a trend.In the four plant communities,BG had the highest activity among the five non-ligninolytic enzymes,and the activities of the two ligninolytic enzymes were higher than those of the four non-ligninolytic ones(AG,NAG,CBH,and BXYL).The community of H.ammodendron displayed the highest activity with respect to the two ligninolytic enzymes in most cases,but no significant differences were found among the four plant communities.The geometric mean of soil enzyme activities of the four plant communities was validated through an independently performed principal component analysis(PCA),which indicated that different plant communities had different soil enzyme activities.The correlation analysis showed that soil polyphenol oxidase activity was significantly positively correlated with the activities of the five non-ligninolytic enzymes.The soil pH value was positively correlated with the activities of all soil enzymes except peroxidase.Soil microbial carbon content also showed a significant positive correlation(P0.01)with the activities of all soil enzymes except polyphenol oxidase.The results suggested that the H.ammodendron community has the highest ability to utilize soil organic carbon,and glucoside could be the most extensively utilized non-ligninolytic carbon source in the saline soil of arid areas in Xinjiang.     

Root growth and spatio-temporal distribution of three common annual halophytes in a saline desert, northern Xinjiang

Root growth and spatial and temporal distribution in the 0-100 cm soil profiles of three common annual halophytes Salsola subcrassa, Suaeda acuminate and Petrosimonia sibirica distributed in a saline desert in northern Xinjiang, China were studied in 2009 and 2010. The results showed that the root systems of the three halophytes were of the taproot type, vertically distributed in the 90-cm soil profile, and were deepest in late July. Their taproots reached maximum depth rapidly, early in the growth period, but with rare lateral roots. They were then dug out in an orderly way, from bottom to top, exhibiting vertical development first and then horizontal development. The distribution of specific root length, which reflects the characteristics of the feeder root, was gradually increased from top to bottom, whereas root weight displayed an opposite distribution pattern. The root length distribution of the three halophytes was concentrated (62% to 76%) in the middle soil profile (20-60 cm), with less distribution in the surface (0-20 cm) and bottom (60-90 cm) soil profiles. The results indicated that the roots of the three annual halophytes grew rapidly into the deeper soil layer after germination, which ensured the plant survival and uptake of water and nutrition, and thus built up a strong tolerance to an arid, high-salt environment.     

降水量和生长方式对红砂和珍珠根系形态特征的影响研究

为揭示典型荒漠植物地下根系对降水变化和种间关系的响应,本研究以红砂(Reaumuria soongorica)和珍珠(Salsola passerina)为材料,通过人工模拟降水变化,测定不同降水量(年降水量50 mm～300 mm,Δ=50)下单生和混生红砂和珍珠的根系形态特征指标.结果表明:随着降水量的增加,单生、...     

荒漠草地四种灌木单株生物量估测方法

研究了砾石荒漠草地下松叶猪毛菜，合头草，中亚木紫菀，和琵琶柴的形体特征与产量的关系，建立了估算四种灌木生物量的回归公式：松叶猪毛菜：ｙ＝－５３．２６２６＋２．３５５Ｘ１＋０．９０６２Ｘ２＋０．５６０６Ｘ３，合头草：ｙ＝－１７．８２２８＋０．９２２６Ｘ１＋０．３９６５Ｘ２＋１．０５３１Ｘ３，中亚木紫菀：ｙ＝－１７．２３５６＋０．７３３９Ｘ１＋０．４０６８Ｘ２＋０．７０３４Ｘ３，琵琶柴：ｙ＝－２１．３     

散枝猪毛菜的果实多型性及个体大小依赖的繁殖输出

对散枝猪毛菜在自然种群中的个体大小、结实和萌发特性进行了观察。结果表明:①自然种群中,散枝猪毛菜具有大小不同的个体,其在植物体干重、株高、分枝级数、节数上具有显著差异,其个体大小表现出极大的可塑性;②散枝猪毛菜产生4种不同类型的果实(种子),并具有不同的萌发行为和散布特性;③依据个体大小的变化,4种类型的果实在植株上的比例发生了显著变化;随着植物个体的增大,A型果实所占比例逐渐增多,由2.253%增加到24.116%,B型果实所占比例逐渐增多,由6.026%增加到41.307%,C型果实所占比例逐渐减少,由81.561%减少到17.709%,D型果实所占比例逐渐增多,由8.077%增加到17.087%。总之,散枝猪毛菜个体大小的表型可塑性和果实多型性是对荒漠异质环境的一种适应。     

新疆几种猪毛菜种子形态、种皮显微构造比较

用JEOL-1200EX型扫描电子显微镜,对新疆准噶尔盆地边缘猪毛菜属4个种的种子微形态进行观察、比较分析,探讨了猪毛菜属部分种子微形态特征的分类学意义。结果表明:猪毛菜种子表面微形态特征具有种的稳定性,与分布区无关;同一种的种子凹、凸面微形态差异很大。同一类群比较时,应选择相同部位观察。所研究的猪毛菜种都为网状(网纹或负网纹)纹饰,种间差异明显。     

盐分、温度对猪毛菜种子萌发的影响

通过对浆果猪毛菜和钠猪毛菜种子在不同盐分、温度环境下的萌发过程与对策研究,结果表明:2种猪毛菜种子萌发的最佳温度约为25 ℃.浆果猪毛菜在蒸馏水中的萌发速度低于钠猪毛菜.浓度低于0.2 mol/L的NaC1溶液对萌发的影响不大;随NaCl浓度增高,浆果猪毛菜和钠猪毛菜种子萌发率降低.一定的盐分胁迫不影响种子萌发潜力,其萌发恢复率随原处理溶液抑制程度的增加而增加.同时,讨论了2种猪毛菜种子萌发特性与环境的关系.     

Separation of two leafhopper populations of theCirculifer haematoceps complex on different host plants in Israel

TwoCirculifer leafhopper populations of thehaematoceps complex have been collected in large numbers in Israel for several years. One of these leafhoppers inhabited prickly saltwort (Salsola kali) plants on sandy soil on the Mediterranean coast. It has a narrow host range and was found to survive for one generation on turnip. The other leafhopper population was collected in 1986 on common goosefoot (Chenopodium album) plants in the Golan Heights. This population is polyphagous and in the laboratory reproduced well onMatthiola incana, turnip, sugar beet andChrysanthemum coronarium; however, reproduction was nil onPhaseolus vulgaris and very low onBrassica oleracea, Portulaca oleracea andCarthamus tinctorius. Contribution from the Agricultural Research Organization. No. 2502-E, 1988 series.