普通菜豆籽粒大小与形状的QTL定位

普通菜豆是世界上最重要的食用豆类作物之一,其籽粒大小和形状与产量及外观品质密切相关。本研究以来自安第斯基因库的大粒品种龙270709和来自中美基因库的小粒品种F5910配置杂交组合,获得的F2分离群体分别在哈尔滨大田与北京昌平温室种植,对百粒重、粒长、粒宽、粒厚、长宽比和长厚比6个籽粒性状进行了相关性分析和QTL定位。相关性分析表明,百粒重与粒长、粒宽、粒厚、长宽比、长厚比5个衡量籽粒大小和形状的性状均显著正相关。利用基于完备区间作图方法的Ici Mapping 4.1进行QTL定位,哈尔滨环境下定位到38个与百粒重、粒长、粒宽、粒厚、长宽比、长厚比相关的QTL,表型贡献率介于2.39%~17.37%之间,分布在除第1染色体外的其余10条染色体上;北京昌平环境下定位到21个上述性状的QTL,表型贡献率介于5.92%~22.53%之间,分布在第1、第3、第6、第7、第8、第9和第11染色体上。其中,百粒重QTLSW7与SW7’,SW6.1与SW6’,粒长QTLSL6.1与SL6.1’,粒厚QTLSH11与SH11’在2个环境下的标记区间重叠或者重合,SW7、SW6.1、SL6.1、SW6’和SL6.1’的表型贡献率在10%以上。     

小麦茎秆实心度对茎秆强度的影响及相关性状QTL分析

在QTL水平上研究茎秆实心度与强度的遗传关系及实心度对茎秆强度的影响,为小麦抗倒伏育种提供依据。利用普通小麦宁麦18与实秆小麦种质"武云实秆"的F2群体和F2:3家系,对小麦茎秆强度、实心度及影响实心度的相关性状包括厚径比、壁厚、茎粗和髓腔直径进行了相关分析,并对茎秆强度相关性状QTL进行分子标记定位及遗传效应分析。结果表明小麦茎秆强度与厚径比、壁厚均呈极显著正相关,与髓腔直径呈极显著负相关。基于复合区间作图法进行QTL定位,检测到与茎秆强度、厚径比、壁厚、茎粗和髓腔直径相关QTL共23个,分布在1B、3B、4A、4B、5A上,表型贡献率3.5%~44.0%。在染色体3B、4A和5A上的标记区间gwm547–gwm247、wmc718–wmc468和gwm156–gwm443均检测到贡献率很高的茎秆实心度相关QTL,说明在这3条染色体上可能存在控制茎秆强度的主效QTL。用普通小麦宁麦13(N13)×武云实秆的24个F7家系检验分子标记gwm247的可靠性表明利用标记gwm247选育茎秆实心度优于宁麦13的概率较大。研究结果为进一步精细定位相关主效QTL以及分子标记辅助改良小麦茎秆强度奠定了基础。     

滇东北4种典型筇竹林凋落物的持水性

以滇东北4种典型筇竹林为研究对象,对比分析不同类型筇竹林凋落物储量及持水性能,从而为滇东北筇竹林生态可持续经营提供理论依据和实践指导。研究结果表明,凋落物储量为人工筇竹-黄皮树混交林（7.61 t/hm²） > 天然筇竹-人工黄皮树混交林（6.61 t/hm²） > 天然筇竹-人工厚朴混交林（5.73 t/hm²） > 天然筇竹纯林（5.23 t/hm²）。凋落物最大持水量为天然筇竹-人工厚朴混交林（3.45 t/hm²） > 人工筇竹-黄皮树混交林（3.22 t/hm²） > 天然筇竹-人工黄皮树混交林（2.89 t/hm²） > 天然筇竹纯林（2.69 t/hm²）。4种类型筇竹林凋落物吸水速率均随着浸泡时间延长而逐渐趋于一致,筇竹混交林凋落物吸水速率高于筇竹纯林。凋落物的总有效拦蓄量为人工筇竹-黄皮树混交林（9.74 t/hm²） > 天然筇竹-人工厚朴混交林（8.95 t/hm²） > 天然筇竹-人工黄皮树混交林（7.73 t/hm²） > 天然筇竹纯林（6.23 t/hm²）。     

Effect of soil pore size distribution on plant-available water and least limiting water range as soil physical quality indicators

Soil pore size distribution(SPSD) is one of the most important soil physical properties. This research investigated the relationships of location and shape parameters of the SPSD curves with plant-available water(PAW) and least limiting water range(LLWR) of the light-textured soils at the Torogh Agricultural Research Station in north-eastern Iran. Soil moisture release curve(SMRC), PAW and LLWR in matric heads of 100 and 330 h Pa for the field capacity and location and shape parameters of the SPSD curves of 30 soils with different texture and organic carbon contents were determined, and the variable relationships were statistically analyzed. The results showed that the median equivalent pore diameter(de), mean de, standard deviation(SD*), and skewness of the SPSD curves were significantly correlated with PAW(PAW330) and LLWR(LLWR330) measured in a matric head of 330 h Pa. Decrease in deand increase in the diversity of soil pore size(SD*) increased PAW330 and LLWR330. The SD* values of all the soil samples were lower than the optimal ranges suggested in literature. Neither PAW nor LLWR values were significantly different in the soils with the optimal modal deand those with non-optimal modal de. Optimal values of median and mean equivalent pore diameters and kurtosis of SPSD curves led to a significant improvement of PAW330 and LLWR330 as soil physical quality indicators. It was recommended to revise the optimal ranges for SD* and modal defor future studies.     

Intensive organic vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated management

Intensive vegetable production in greenhouses has rapidly expanded in China since the 1990s and increased to 1.3 million ha of farmland by 2016, which is the highest in the world. We conducted an 11‐year greenhouse vegetable production experiment from 2002 to 2013 to observe soil organic carbon (SOC) dynamics under three management systems, i.e., conventional (CON), integrated (ING), and intensive organic (ORG) farming. Soil samples (0–20 and 20–40 cm depth) were collected in 2002 and 2013 and separated into four particle‐size fractions, i.e., coarse sand (> 250 µm), fine sand (250–53 µm), silt (53–2 µm), and clay (< 2 µm). The SOC contents and δ¹³C values of the whole soil and the four particle‐size fractions were analyzed. After 11 years of vegetable farming, ORG and ING significantly increased SOC stocks (0–20 cm) by 4008 ± 36.6 and 2880 ± 365 kg C ha^?1 y^?1, respectively, 8.1‐ and 5.8‐times that of CON (494 ± 42.6 kg C ha^?1 y^?1). The SOC stock increase in ORG at 20–40 cm depth was 245 ± 66.4 kg C ha^?1 y^?1, significantly higher than in ING (66 ± 13.4 kg C ha^?1 y^?1) and CON (109 ± 44.8 kg C ha^?1 y^?1). Analyses of ¹³C revealed a significant increase in newly produced SOC in both soil layers in ORG. However, the carbon conversion efficiency (CE: increased organic carbon in soil divided by organic carbon input) was lower in ORG (14.4%–21.7%) than in ING (18.2%–27.4%). Among the four particle‐sizes in the 0–20 cm layer, the silt fraction exhibited the largest proportion of increase in SOC content (57.8% and 55.4% of the SOC increase in ORG and ING, respectively). A similar trend was detected in the 20–40 cm soil layer. Over all, intensive organic (ORG) vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated (ING) management.     

茶树凋落叶浸提液对菘蓝生理生化的化感效应

为研究茶树凋落叶浸提液对菘蓝生长与生理生化的化感效应,以模拟自然条件下雨雾淋溶方式,采用不同浓度的茶树凋落叶浸提液(CK:0 mg·mL^-1、T1:6.25 mg·mL^-1、T2:12.5 mg·mL^-1、T3:25 mg·mL^-1 和T4:50 mg·mL^-1)处理菘蓝,测定其生长、抗氧化酶活性及其基因表达量、细胞膜损伤率以及丙二醛(MDA)、过氧化氢(H₂O₂)、渗透调节物质和次生代谢物含量的变化。结果表明,茶树凋落叶浸提液对菘蓝生长表现出“低促高抑”的浓度效应,与CK相比,T1对菘蓝生长具有一定的促进作用,而浸提液浓度超过菘蓝的耐受阈值时,会对其生长产生不利的影响。随着浸提液浓度的升高,可溶性糖和可溶性蛋白含量呈先上升后下降的趋势,而脯氨酸含量则持续增加。与CK相比,T1的MDA含量、细胞膜损伤率和H₂O含量差异不显著,而T3、T4则显著升高。茶树凋落叶浸提液对抗氧化酶活性及其基因表达有不同的影响,T1的过氧化物酶(POD)与抗坏血酸氧化物酶(APX)活性最高,T2的过氧化氢酶(CAT)活性最高,而T3、T4的4种抗氧化酶活性均显著低于CK。T1的Pod、Cat、Apx基因表达量最高,而T4则抑制了抗氧化酶基因的表达。此外,POD活性与其基因表达量呈显著正相关,而超氧化物歧化酶(SOD)、CAT和APX活性与其基因表达量的相关性不显著。不同浓度的茶树凋落叶浸提液对于菘蓝次生代谢物质积累的影响存在显著差异,低浓度茶树凋落叶浸提液对菘蓝生长、靛蓝和靛玉红含量积累有促进作用,而高浓度茶树凋落叶浸提液对总黄酮含量积累有一定的促进作用。本研究结果可为幼龄茶园中茶树-菘蓝复合种植提供理论参考。     

玉米LFY同源基因ZFL1与多叶性状的相关性

LFY基因是控制拟南芥花分生组织特异性的关键基因,该基因的突变会引起延迟开花和叶片形态变化。本试验以相同核背景(Y53)下穗上叶片数14叶和4叶的材料为模板,通过PCR反应,扩增出4条ZFL1基因目的片段。对PCR扩增产物进行回收、纯化和测序,将测序片段进行拼接。通过序列比对,结果表明与Y53(4L)相比较,Y53(14L)在外显子3有一段13 bp的重复序列,造成ORF的改变,进而引起氨基酸序列改变。据此,初步认为多叶玉米ZFL1基因在外显子区域发生突变造成表达产物-转录因子结合靶基因的功能性失活,使玉米营养生长阶段延迟,从而引起玉米穗上叶片数的增加。     

水稻苗期耐冷性研究进展

就我国水稻苗期耐冷性的鉴定与评价、遗传、分子标记和育种与选择效应等方面的研究进展进行了阐述。并对今后水稻的耐冷性研究提出了建议和展望。     

多花黑麦草新品系产量及农艺性状研究初探

试验对多花黑麦草新品系的植物学性状、农艺性状、生长动态及拔节期营养物质含量进行了研究。结果表明,多花黑麦草新品系生育期为234 d,生长发育迅速,特别是冬春季生长优势明显;年产草量(DM)可达15 469kg/hm2;植株高大,叶量丰富、叶片宽大,拔节期粗蛋白含量达16.17％,表现出明显的优良牧草性状;在南方亚热带地区生长良好,是优良的多花黑麦草新品系。