Root characteristics of Alhagi sparsifolia seedlings in response to water supplement in an arid region,northwestern China

The effect of variation in water supply on woody seedling growth in arid environments remain poorly known.The subshrub Alhagi sparsifolia Shap.(Leguminosae),distributed in the southern fringe of the Taklimakan Desert,Xinjiang,northwestern China,has evolved deep roots and is exclusively dependent on groundwater,and performs a crucial role for the local ecological safety.In the Cele oasis,we studied the responses of A.sparsifolia seedling roots to water supplement at 10 and 14 weeks under three irrigation treatments(none water supply of 0 m3/m2(NW),middle water supply of 0.1 m3/m2(MW),and high water supply of 0.2 m3/m2(HW)).The results showed that the variations of soil water content(SWC) significantly influenced the root growth of A.sparsifolia seedlings.The leaf area,basal diameter and crown diameter were significantly higher in the HW treatment than in the other treatments.The biomass,root surface area(RSA),root depth and relative growth rate(RGR) of A.sparsifolia roots were all significantly higher in the NW treatment than in the HW and MW treatments at 10 weeks.However,these root parameters were significantly lower in the NW treatment than in the other treatments at 14 weeks.When SWC continued to decline as the experiment went on(until less than 8% gravimetric SWC),the seedlings still showed drought tolerance through morphological and physiological responses,but root growth suffered serious water stress compared to better water supply treatments.According to our study,keeping a minimum gravimetric SWC of 8% might be important for the growth and establishment of A.sparsifolia during the early growth stage.These results will not only enrich our knowledge of the responses of woody seedlings to various water availabilities,but also provide a new insight to successfully establish and manage A.sparsifolia in arid environments,further supporting the sustainable development of oases.     

干旱荒漠区骆驼刺资源及利用

骆驼刺是一种耐盐、抗旱、蛋白质含量丰富的多年生豆科牧草.利用干旱荒漠区大量盐碱地和荒地等未利用土地进行人工种植,可以改土治沙,抑制草场退化,提供饲料,实现经济、生态和社会效益三统一的综合效益.     

骆驼的饲养技术

随着时代的变迁,有“沙漠之舟”美誉的骆驼已形成产业且衍生出更多商机,作为阿勒泰地区畜牧业大县的富蕴县的驼业逐渐成为农牧们主要经济来源以及改善民生起着重要作用,同时,历来成为哈萨克族饮食文化中不可缺少的主要饮料之一,骆驼奶及相关产品受到越来越多的关注,因此,需要传统养驼业由现代羊驼业来代替,此外,有经验的老养驼户数量减少而较为年轻养驼户经验不丰富,总之,发展羊驼业需要丰富的养殖经营知识。     

盐胁迫条件下骆驼刺与绿豆光合日变化特征及午休现象的成因

为了研究盐生豆科植物骆驼刺与盐敏感植物绿豆在盐胁迫下光合日变化与光合“午休”现象的成因,在网室培养,并用0 mmol•L^-1(对照)、50 mmol•L^-1、100mmol•L^-1、200 mmol•L^-1 NaCl处理2周,测定光合作用日变化、叶绿素含量和Rubisco大亚基基因的表达等参数。结果表明：未经盐处理时,骆驼刺和绿豆光合日变化均呈单峰型;经盐处理后,两者光合日变化响应有明显差异。骆驼刺50～200 mmol•L^-1NaCl处理后,其净光合速率（Pn）均比未处理(对照)上升速率快,而其他处理峰值与对照之间没有显著差异;绿豆对照光合速率的上升则比盐处理的快,盐处理光合速率峰值低于对照。骆驼刺50 mmol•L^-1、100 mmol•L^-1和绿豆50 mmol•L^-1处理Pn没有出现“午休”现象,而骆驼刺200 mmol•L^-1处理与绿豆100 mmol•L^-1处理出现“午休”现象。骆驼刺在重度盐胁迫下,由于气孔导度（Gs）下降而引起轻微的“午休”现象,而盐处理绿豆中Rubisco被抑制,对Pn 午休的贡献比其Gs的贡献更为显著。在绿豆中大亚基基因（rbcL）的表达量随着盐胁迫的提高而下降。骆驼刺中rbcL的表达在50 mmol•L^-1和100 mmol•L^-1处理下有所增加,而在200 mmol•L^-1处理显著降低。绿豆和骆驼刺的总叶绿素含量及其Chl a/b比值的动态变化表明,绿豆PSI复合体下降速率较PSII快;与此相反,骆驼刺盐处理后PSI复合体浓度的增加却比PSII复合体快。     

骆驼刺染色体数目及核型分析

采用常规根尖压片法对分布于内蒙古自治区阿拉善荒漠地区的骆驼刺(Alhagi maurorum Medil.var.sparsifolium(Shap.)Yakovl.)染色体数目与核型进行了研究分析。结果表明:骆驼刺染色体数目为16条,二倍体。核型公式为2n=2x=16=12m+4sm,核型不对称系数为58.86%,核型类型属于2B型。     

你有几条根

看似寻常的植物,其实并不简单:抽穗期,冬黑麦的根共有约1400万条。如果把它们圈连,总长度可达600公里以上。沙漠中的骆驼刺儿根入土可达20米有余。青香蕉的根向四周延伸,直径可达27米。植物通过增加侧根,加深长度,扩大面积,来吸收尽     

结实期骆驼刺与紫花苜蓿混贮效果的研究

本试验旨在确定结实期骆驼刺与紫花苜蓿混贮能否获得优良的青贮品质及其适宜混贮比例。采用单一苜蓿、单一骆驼刺及其二者不同重量百分比混合料(30%骆驼刺+70%苜蓿、50%骆驼刺+50%苜蓿、70%骆驼刺+30%苜蓿)为青贮原料,共5个处理,每个处理3个重复。通过分析青贮前、后的化学成分,鉴定青贮饲料感官品质和发酵品质。结果表明:2种牧草混合后,与单一苜蓿相比,显著或极显著提高了青贮原料的干物质、酸性洗涤纤维、中性洗涤纤维和可溶性碳水化合物含量(P<0.05或P<0.01);青贮90 d后,混贮料的乙酸含量显著高于单一骆驼刺青贮(P<0.05),单一骆驼刺青贮中未检测出丙酸含量;混贮料的氨态氮/总氮、p H、乙酸、丙酸、正丁酸、异丁酸、异戊酸、甲醇含量显著或极显著低于单一苜蓿青贮(P<0.05或P<0.01),其乳酸含量和乳酸/乙酸显著或极显著高于单一苜蓿青贮(P<0.05或P<0.01)。因此,混贮达到了既能改善苜蓿的发酵品质,又能软化骆驼刺的刺状花梗的目的,感官品质优良;骆驼刺占混贮料的30%时,可改善苜蓿青贮品质。