不同高丹草品种对干旱胁迫的响应及抗旱性评价

采用全生育期田间模拟干旱法,设置"正常浇水"和"干旱胁迫"2个处理,从生长发育特性、品质以及产量性状方面研究了自育高丹草(Sorghum bicolor×S.sudanense)新品种(冀草1号、冀草2号)与生产中主推品种(皖草3号、乐食、健宝)在抗旱性上的差异,借鉴小麦抗旱鉴定技术规范中的抗旱指数(Drought index,DI)对参试品种进行抗旱性评价。结果表明:各单项指标的性状抗旱系数(Drought resistance coefficient,DRC)显示干旱胁迫降低了植株株高、草产量、鲜干比及粗蛋白含量,增加了主茎糖锤度含量,对茎叶比影响较小;相同指标的性状抗旱系数在不同品种间差异性表现不同。运用DI得出,鲜草产量下各品种抗旱性排序为冀草1号>冀草2号>乐食>健宝>皖草3号,干草产量下各品种抗旱性排序为冀草1号>皖草3号>冀草2号>乐食>健宝。     

新疆耐盐水稻种质资源的筛选

在0、3、6、9、12和15 g/L 5个NaCl单盐浓度下,对40份新疆引进或自育的水稻种质资源进行鉴定和筛选,以期获得极端耐盐水稻种质资源,同时研究了不同NaCl溶液对水稻发芽率的影响.结果表明:发芽率、芽长、根长、根数均随盐浓度升高而呈下降趋势,高浓度盐溶液显著抑制水稻种子的发芽率,但材料间有较大差异;延迟种子发芽时间,抑制生育进程;筛选出芽期极端耐盐品种6份,其中2级3份,3级2份,4级1份.     

Water management options based on rainfall analysis for rainfed maize (Zea mays L.) production in Rushinga district, Zimbabwe

Maize (Zea mays L.), the dominant and staple food crop in Southern and Eastern Africa, is preferred to the drought-tolerant sorghum and pearl millet even in semi-arid areas. In semi-arid areas production of maize is constrained by droughts and poor rainfall distribution. The best way to grow crops in these areas is through irrigation, but limited areal extent, increasing water scarcity, and prohibitive development costs limit the feasibility of irrigation. Therefore, there is need for a policy shift towards other viable options. This paper presents daily rainfall analysis from Rushinga district, a semi-arid location in Northern Zimbabwe. The purpose of the rainfall analysis was to assess opportunities and limitations for rainfed maize production using 25 years of data. Data was analysed using a variety of statistical methods that include trend analysis, t-test for independent samples, rank-based frequency analysis, Spearman's correlation coefficient and Mann-Whitney's U test. The results showed no evidence of change in rainfall pattern. The mean seasonal rainfall was 631 mm with a standard deviation (SD) of 175 mm. December, January and February consistently remained the major rainfall months. The results depicted high inter-annual variability for both annual and seasonal rainfall totals, a high incidence of droughts ≥3 out of every 10 years and ≥1 wet year in 10 years. Using the planting criteria recommended in Zimbabwe, most of the plantings would occur from the third decade of November with the mode being the first decade of December. This predisposes the rainfall to high evaporation and runoff losses especially in December when the crop is still in its initial stage of growth. On average 5 to more than 20 days dry spells occupy 56% of the rainy season. Seasonal rainfall exhibited negative correlation (P < 0.001; R = −0.746) with cumulative dry spell length, and wet years were free from dry spells exceeding 20 days. The most common dry spells (6-10 days), are in the range in which irrigated crops survive on available soil water. Therefore, they can be mitigated by in situ rainwater harvesting (RWH) and water conservation. The potential evapotranspiration of a 140-day maize crop was estimated to be 540 mm. Consequently, short season maize cultivars that mature in less than 140 days could be grown successfully in this area in all but drought years. However, sustainable maize production can only be achieved with careful management of the soil as a medium for storing water, which is essential for buffering against dry spells. To this end soil restorative farming systems are recommended such as conservation farming, in situ RWH techniques for dry spell mitigation and a cropping system that includes drought-tolerant cereal crops as for example sorghum and pearl millet, and perennial carbohydrate sources as for example cassava to provide stable crop yields.     

干旱胁迫及复水对棉花叶片氮代谢的影响

以不同抗旱型棉花品种新陆早7号和新陆早24号幼苗为试材,研究持续干旱胁迫及复水对棉花幼苗叶片氮代谢关键酶活性、可溶性蛋白质、总氮和游离氨基酸含量的影响。结果显示:随着干旱胁迫天数的增加,新陆早7号和新陆早24号硝酸还原酶(NR)活性与对照相比分别降低 51.67%和74.22%;谷氨酰胺合成酶(GS)活性分别降低50.65%和72.95%;谷氨酸合成酶(GOGAT)活性分别降低 43.11%和68.36%;谷氨酸脱氢酶(GDH)活性在处理4d达到最大值;可溶性蛋白质含量分别增加了56.96%和34.12%;总氮含量分别增加了11.39%和8.43%;内肽酶活性分别增加了115.76%和165.06%;铵离子含量分别增加了92.29%和111.56%。干旱胁迫使新陆早7号在胁迫前期游离氨基酸含量增加慢,后期增加快;新陆早24号游离氨基酸含量的变化趋势与新陆早7号则相反。复水后,新陆早7号 NR、GS、GOGAT和GDH等活性恢复较快,内肽酶活性和游离氨基酸、铵离子、可溶性蛋白质和总氮含量下降也较快。试验表明,抗旱棉花品种具有较强的铵离子同化能力,增加渗透调节物质游离氨基酸含量,特别是脯氨酸含量增强其耐旱性。     

Yield constraints of rainfed lowland rice in Central Java, Indonesia

The low and unstable yields of rainfed lowland rice in Central Java can be attributed to drought, nutrient stress, pest infestation or a combination of these factors. Field experiments were conducted in six crop seasons from 1997 to 2000 at Jakenan Experiment Station to quantify the yield loss due to these factors. Experimental treatments—two water supply levels (well-watered, rainfed) in the main plots and five fertilizer levels (0-22-90, 120-0-90, 120-22-0, 120-22-90, 144-27-108 kg NPK ha⁻¹) in the subplots—were laid out in a split-plot design with four replications. Crop, soil, and water parameters were recorded and pest infestations were assessed.

In all seasons, rice yield was significantly influenced by fertilizer treatments. Average yield reduction due to N omission was 42%, to K omission 33–36%, and to P omission 3–4%. Water by nutrient interactions did not affect rice yield and biomass production. In two of the three dry seasons, an average of 20% of the panicles were damaged by pests and estimated yield loss from pests was 56–59% in well-watered and well-fertilized treatments. In one out of six seasons, yields under rainfed conditions were 20–23% lower than under well-watered conditions. Drought, N and K deficiencies, and pest infestation are the major determinants for high yields in rainfed environments in Jakenan. Supplying adequate nutrient and good pest control are at least as important as drought management for increasing crop productivity of rainfed rice-growing areas in Central Java. The relative importance of drought, nutrient and pest management may vary in other rainfed areas. Yield constraints analysis should be systematically carried out to identify appropriate management strategies.     

干旱胁迫对豫楸1号嫁接苗的生理生化影响研究

以1年生豫楸1号四种砧木嫁接苗(金丝楸、豫楸1号、灰楸和梓树)为试验材料通过盆栽干旱胁迫以正常浇水处理为对照,研究了不同程度干旱胁迫对这四种不同砧木豫楸1号嫁接苗在保护酶活性、脂膜透性、过氧化物的反应物积累和细胞渗透调节性物质等方面的生理生化影响。结果表明:保护酶SOD活性先上升后下降,活性表现明显的是金丝楸嫁接苗;MDA的积累都有明显增加,金丝楸嫁接苗积累最少,增加较多的是梓树嫁接苗和灰楸嫁接苗;脂膜透性都有不同程度的上升,其中梓树嫁接苗和灰楸嫁接苗上升较快,金丝楸嫁接苗积累较少。可溶性蛋白的含量都有不同程度的上升,其中金丝楸嫁接苗积累较多。经过对几项生理指标的综合方差[1]分析,认为金丝楸嫁接苗相对于其他三个品种具有较强的抗旱能力。     

黄淮海麦区部分小麦品种的抗旱性评价及相关分子标记的有效性验证

为研究黄淮海麦区小麦品种的抗旱性,对黄淮海麦区46个小麦品种萌发期的抗旱性进行鉴定,验证3个抗旱性相关分子标记的有效性,并利用分子标记检测抗旱性相关基因 1-feh-w3、 TaDreb-B1、 TaNRX-B1的单倍型分布。结果显示,供试材料的平均相对发芽率为64.8%,变化范围为30.7%~95.4%,中等及以上抗旱性等级小麦品种占比84.8%。 1-feh-w3基因的Westonia type单倍型平均相对发芽率显著高于Kauz type单倍型,但与相对发芽率相关性并不显著。 TaNRX-B1基因的 TaNRX-B1a单倍型平均相对发芽率显著高于 TaNRX-B1b单倍型,且与相对发芽率显著相关。 TaDreb-B1基因的 TaDreb-B1a单倍型平均相对发芽率显著高于 TaDreb-B1b单倍型,品种占比达到95.7%,在小麦抗旱性中起重要作用,与相对发芽率相关性也不显著。单倍型组合Westonia type/TaDreb-B1a/TaNRX-B1a的平均相对发芽率最高,为76.79%。筛选出抗旱性较好的小麦品种14个,分别为徐麦36、中植0914、囤麦127、洛麦26、百农418、齐民7号、丰德存麦20、丰德存麦12、丰德存麦1号、赛德麦7号、驻麦328、周麦32、国红3号和迁麦088,可以在小麦育种中作为抗旱种质加以利用。     

耐盐抗旱优质高产棉花新品种‘衡棉1670’的选育研究

抗逆优质丰产棉花新品种的培育及应用是当前棉花生产节水提质增效的关键。‘衡棉1670’是河北省农林科学院旱作农业研究所以中早熟陆地棉品种资源材料‘衡棉210’为母本,以‘衡棉4号’为父本杂交,后代多年南繁北育,经旱棚盐池鉴定选择,在枯黄萎病混生重病地、不防治棉铃虫的高压胁迫下,经过多年连续定向选择育成。其突出表现为抗枯黄萎病、丰产优质、耐盐抗旱节水,适宜在河北省及黄河流域同类生态春播棉区推广种植,2019年8月通过河北省农作物品种审定委员会审定（审定编号为冀审棉20190013）。     

几种攀缘植物耐旱性研究

用渗透势法测定了几种植物水合补偿点，对十八种植物的叶相对含水量，水分饱和亏缺，肉质化程度，比叶面积进行了测定，并用系统聚类的方法对其耐旱能力进行了综合评价。