新疆喀什棉铃虫敏感性基因保护研究

从新疆喀什采集棉铃虫（Helicoverpa armigera Huebner)在室内建立实验种群,以点滴法测定了该种群对31种杀虫剂的敏感性毒力数据,对所测得的毒力基线进行了排队分析。结果表明,新疆喀什棉区棉铃虫对拟除虫菊酯类杀虫剂、部分有机磷酸酯类杀虫剂如久效磷、丙溴磷、辛硫磷、甲胺磷、蔬果磷和甲基对硫磷等表现敏感;对氨基甲酸酯类的灭多威敏感度接近敏感毒力基线。而对有机磷酸酯类的另一些品种如亚胺硫磷、氧乐果、倍硫磷、敌百虫及其他品种如硫双灭多威、异丙威和硫丹等却表现高度耐性。最后,就新疆棉区棉铃虫对杀虫剂敏感性基因保护进行了讨论。     

Shade response of bermudagrass accessions under different management practices

The development of cultivars ‘TifGrand’ and ‘Celebration’ has shown potential increases in shade tolerance compared to previous industry standards of bermudagrass (Cynodon spp.). Based on the literature, further improvements in shade tolerance can be attained through changes in nitrogen fertility rates, mowing heights, and the application of plant growth regulators. In this study, two South African hybrid (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy) bermudagrass accessions (‘WIN10F’ and ‘STIL03’) and three standard cultivars (Celebration, Tifgrand, and ‘Tifway’) were compared for their ability to persist under 63% shade, two mowing heights, two trinexapac-ethyl (TE) treatments, and two nitrogen fertility rates. The experimental design was a strip-strip-split plot and digital image analysis was used to measure percent turfgrass cover, percent turfgrass spread after cup-cutter removal, and percent turfgrass re-growth after divot formation. Turf quality was measured using the normalized difference vegetation index (NDVI). Differences among genotypes, TE treatments, and mowing heights were observed across all response variables in 2014 and 2015. Differences in fertility treatments were observed in NDVI, percent turfgrass growth, and percent turfgrass recovery within and across years. Significant differences were observed for the interactions between entry by plant growth regulator (PGR) treatments, entry by mowing height, and mowing height by PGR. These results suggest shade management recommendations should be dependent on genotype and site-specific considerations. The development and implementation of specific management plans for certain bermudagrass varieties will contribute to the more widespread use of Cynodon spp. in shaded environments.     

水淹条件下狗牙根对镉胁迫的生理生化响应

为了研究狗牙根分别经受水淹、镉胁迫和同时经受水淹和镉胁迫的生理生化响应。以野生狗牙根为试验材料,采取模拟盆栽的试验方法,设置8个不同处理。结果表明:水淹在一定程度上能促进狗牙根茎、叶的生长、抗氧化酶活性的升高以及对Cd~(2+)的吸收,同时也会抑制狗牙根根系的生长以及叶绿素的合成;镉胁迫下随着浓度的升高会使得狗牙根膜脂过氧化程度加剧,同时也会刺激其抗氧化酶活性增加来减少逆境所造成的伤害,并且POD、SOD、CAT 3种酶活在不同Cd~(2+)浓度下表达不同;狗牙根不同部位吸收镉的能力表现为:叶根茎,且对镉的耐受阈值达到了150 mg/L,其富集系数大于1、转运系数大于0.5。在镉胁迫的伤害阈值内狗牙根可以正常生长,其可作为同时遭受水淹和重金属污染地区植被恢复的优良物种。     

进口百慕达草截获水稻干尖线虫及其除害处理

从惠州港进口产自美国夏威夷的百慕达草中发现我国进境植物检疫潜在危险性线虫——水稻干尖线虫ＡｐｈｅｌｅｎｃｈｏｉｄｅｓｂｅｓｅｙｉＣｈｒｉｓｔｉｅ,１９４２。已对所有百慕达草实行隔离种植,并在种植期间用４５ｋｇ／ｈｍ２涕灭威进行除害处理２次,该线虫已得到控制。     

狗牙根种质资源在渝西地区的生态适应性评价

通过对种植于荣昌的狗牙根Cynodon dactylon试验材料应用“9分制”评分法进行打分开展综合评价,结合叶长、叶宽等形态指标的观测,对比分析7个狗牙根品种（系）在生长发育期的表现,反映其在渝西地区自然生态环境下的适应性强弱。结果表明TIFWAY、SAU9936极显著优于其他5个品种(系),而SAU02014与SAU02011、SAU9928间无显著差异,但他们显著优于南京、SAU9926,其综合评定得分为: TIFWAY＞SAU9936＞SAU02014＞SAU02011＞SAU9928＞南京＞SAU9926。供试的狗牙根7个品种(系)在渝西地区自然生态环境下都完成整个生育期,有比较强的适应性,其中TIFWAY、SAU9936适应性最强,其次是SAU02014、SAU02011,再次是SAU9928、南京,SAU9926最差。     

Evaluation of a crop water stress index for irrigation scheduling of bermudagrass

This study was conducted to assess crop water stress index (CWSI) of bermudagrass used widely on the recreational sites of the Mediterranean Region and to study the possibilities of utilization of infrared thermometry to schedule irrigation of bermudagrass. Four different irrigation treatments were examined: 100% (I₁), 75% (I₂), 50% (I₃), and 25% (I₄) of the evaporation measured in a Class A pan. In addition, a non-irrigated treatment was set up to determine CWSI values. The status of soil water content and pressure was monitored using a neutron probe and tensiometers. Meanwhile the canopy temperature of bermudagrass was measured with the infrared thermometry. The empirical method was used to compute the CWSI values. In this study, the visual quality of bermudagrass was monitored seasonally using a color scale. The best visual quality was obtained from I₁ and I₂ treatments. Average seasonal CWSI values were determined as 0.086, 0.102, 0.165, and 0.394 for I₁, I₂, I₃, and I₄ irrigation treatments, respectively, and 0.899 for non-irrigated plot. An empirical non-linear equation, Qave=1+⌊6[1+(4.853 CWSIave)^2.27]^−0.559⌋$Q_{\text{ave}}=1+⌊6{[1+{(4.853\text{CWS}{\text{I}}_{\text{ave}})}^{2.27}]}^{-0.559}⌋$, was deduced by fitting to measured data to find a relation between quality and average seasonal CWSI values. It was concluded that the CWSI could be used as a criterion for irrigation timing of bermudagrass. An acceptable color quality could be sustained seasonally if the CWSI value can be kept about 0.10.     

用野生狗牙根草绿化湖南高速公路石方边坡的试验研究

开发利用野生植物资源绿化高速公路边坡,具有广阔的市场前景.野生狗牙根草具有生长快、抗性强的特点,采取挂网式等技术措施,对湖南潭邵高速公路的部分石方边坡用野生狗牙根草进行绿化试验,结果表明,与传统的石方边坡客土喷播草种方法相比,不但成本低,而且坡面覆盖快,水土保持和绿化效果好.     

Comparison of acid-detergent lignin,alkaline-peroxide lignin,and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

Background:The potential for acid-detergent insoluble ash(ADIA),alkaline-peroxide lignin(APL),and acid-detergent lignin(ADL) to predict fecal output(FO) and dry matter digestibility(DMD) by cattle offered bermudagrass[Cynodon dactylon(L.) Pers.]hays of different qualities was evaluated.Eight ruminally cannulated cows(594 ± 35.5 kg) were allocated randomly to 4 hay diets:low(L),medium low(ML),medium high(MH),and high(H) crude protein(CP)concentration(79,111,131,and 164 g CP/kg on a DM basis,respectively).Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods.Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection.Actual DM intake(DMI),DMD,and FO were determined based on hay offered,ort,and feces excreted.These components were then analyzed for ADL,APL,and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD.Results:Forage DMI was affected by diet(P = 0.02),and DMI from MH and H was greater(P 0.05) than from L.Apparent DMD tended(P = 0.08) to differ among diets while FO(P = 0.20) was not affected by diet treatments.Average ADL recovery(1.16) was greater(P 0.05) than that of ADIA(1.03) and APL(1.06),but ADIA and APL did not differ(P = 0.42).Estimates of FO and DMD derived using APL and ADIA were not different(P 0.05) from total fecal collection while those using ADL differed(P 0.05).There was no diet by marker interaction(P 0.22)for either FO or DMD.Conclusion:Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition.These internal markers may facilitate studies involving large numbers of animals and forages.Results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of dietary components to digestibility across a wide range of forages.     

Genetic diversity of Chinese natural bermudagrass (Cynodon dactylon) germplasm using ISSR markers

Bermudagrass (Cynodon dactylon L.) is an important warm-season turfgrass. Although it is widely distributed in China, studies on the genetic variation and relationship among the large-scale indigenous bermudagrass were relatively insufficient, especially at molecular level. The purpose of this study was to assess the molecular variation and relationship among one commercial cultivar ‘Tift3’ and 95 wild bermudagrass accessions collected from 11 provinces in China by ISSR marker technique. The results indicated that 29 ISSR primers generated a total of 248 bands among which 242 (97.6%) were polymorphic bands. The genetic similarity coefficients among accessions ranged from 0.51 to 0.97 with an average of 0.74. All accessions could be clustered into 11 groups with UPGMA method. Accessions from the same or adjacent regions generally were clustered into the same group or subgroups. A few accessions, however, were greatly different from the majority of all accessions. The results suggested that ISSR marker is an effective tool for the study of genetic variation in Chinese natural bermudagrass.     

深淹对狗牙根根际土壤酶活性及肥力的影响

以三峡库区消落带生境和非消落带生境生长的狗牙根(XC、FC)为试验材料, 研究了不同生境狗牙根经不同深度水淹胁迫后, 植株根际土壤酶活性和土壤肥力状况。结果表明: 未淹对照植株根际土壤的蔗糖酶活性明显大于不同深度淹水处理, 说明淹水处理不能给植物提供与未淹对照同样多的营养源; FC 根际土壤的脲酶和酸性磷酸酶活性都较XC 的高; 淹水处理后, FC 根际土壤的全氮含量明显低于XC; 淹水前FC 根际土壤的全磷含量明显高于XC, 表明在未进行淹水处理之前的生长时期, XC 可能较FC 利用更多的土壤营养进行生长, 储备更多的能量, 从而为淹水期间植株提供能量供应, 为增强其耐淹能力奠定较好的能量基础。以上结果说明不同生境狗牙根在不同水淹胁迫下, 植株根际土壤酶活性和土壤肥力的变化与其耐淹能力有关。