Tree growth performance and estimation of wood quality in plantation trials for Maesopsis eminii and Shorea spp.

Plantations of tropical species axe becoming an increasingly important source of wood. However, it is important that research trials focus not only on tree growth performance, but also on wood quality. The aims of this study were to assess the growth performance of six commercially and ecologically important tree species from separate plantation trials in Indonesia and to determine the relationships between tree growth and wood quality in terms of the dynamic modulus of elasticity （MOE） and wood density. Forty-eight 7-year Maesopsis eminii Engl. and thirty-five 9-year specimens （7 each of 5 Shorea spp.） were selected from two trials. The MOE, based on acoustic velocity, was indirectly measured to evaluate wood stiffness. Tree-growth performance was evaluated, and correlations between growth traits and acoustic velocity as well as density and wood stiffness properties were estimated. The growth performance of M. eminii in terms of tree volume was significantly different in three different cate- gories of growth （i.e. fast, medium, slow）. Of the five Shorea spp. studied, Shorea leprosula Miq. had the highest growth rate, as expected since it is known to be a fastgrowing Shorea species. Indirect measurement of wood quality by means of non-destructive ultrasonic methods showed a weak negative correlation between tree volume and acoustic velocity and dynamic MOE. Although each fast-growing tree could reach a merchantable size faster than other varieties or species, wood traits of various species tested were not significantly different based on tree growth rate performance. The findings from this study could be used to improve selection criteria in future breeding trials; indirect measurements of the dynamic modulus of elasticity can be used in mass pre-selection of genetic materials, to choose the most-promising material for in-depth evaluation.

Effects of Growth Period on Quality and Tuber Traits of New Sweetpotato Cultivar Xuzishu 8

Xuzishu 8 is a new cultivated sweetpotato with high anthocyanidin content.The growth period affects its tuber traits and quality.In this study,the changes in sweetpotato shape,number of tubers per plant,rate of big and medium tubers,yield,anthocyanin content and starch content of Xuzishu 8 were investigated under 12 growth periods from 78 to 188 d.The results showed that various traits of Xuzishu 8 were significantly different between different growth periods.The rate of large and medium tubers,the fresh sweetpotato yield,the starch content and the anthocyanin yield increased gradually with the extension of the growth period.The length/width ratio of sweetpotato tubers,the rate of small tubers and the contents of reducing sugar and soluble sugar decreased with the prolongation of the growth period.The correlation analysis showed that the fresh sweetpotato yield was in significant or extremely significant positive correlation with the number of tubers per plant,rate of big and medium tubers,dry matter content,dry yield and starch content.The 148-day growth period treatment exhibited the highest number of tubers per plant,the highest fresh sweetpotato yield and anthocyanin yield reaching 3 927 and 4.25 kg/667 m^2,respectively,as well as the rate of large and medium tubers up to 90%.Therefore,the tubers had good marketability and eating quality.

Variation analyses of growth and wood properties of Larix olgensis clones in China

The growth traits (tree height, diameter at breast height, and stem straightness degree) and wood properties [wood density (WD), fiber length, fiber width, ash content (AC), lignin content, cellulose content, hemicellulose content (HEC), and holocellulose content] of 208 26-year-old Larix olgensis clones were analyzed. Except for WD and AC, there were significant differences (p < 0.01) for all traits among clones. The phenotypic coefficient of variation and repeatability of all traits were 9.34-35.33% and 0.218-0.930, respectively. Tree height and diameter at breast height showed significant positive correlation; however, the correlation coefficients among growth characteristics and wood properties were mostly not significant. Ten clones (L70, L56, L82, L90, L59, L91, L61, L92, L86, and L64) were selected as excellent clones under a selection rate of 5%, using tree height, diameter at breast height, and stem straightness degree as evaluation indexes, providing genetic gains of 28.69, 17.96, and 0.67%, respectively. Ten clones (L88, L305, L59, L66, L253, L304, L277, L298, L248, and L293) were selected as excellent clones using wood properties as an evaluation index, with a selection rate of 5%, providing genetic gains in WD, fiber length, fiber width, cellulose content, and HEC of 4.14, 3.64, 9.28, 6.77, and 9.61%, respectively. This study provides a theoretical basis for selecting excellent L. olgensis clones.

Age trends and correlations of growth and wood properties in clone of Eucalyptus urophylla × E. grandis in Guangdong, China

We assessed growth traits and wood properties ofDH32-29, a clone of Eucalyptus urophylla x E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences （1% level） on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from -0.03 to -0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year. Correlations between Pilodyn pin penetration and basic density measured on increment cores showed that Pilodyn could rank or group genotypes or sites into density classes, but failure to predict individual tree and individual clone.

Variations in growth traits and wood physicochemical properties among Pinus koraiensis families in Northeast China

This study aimed to explore and improve the different economic values of Pinus koraiensis(Siebold and Zucc.)by examining the variations in 6 growth traits and 9 physicochemical wood properties among 53 P.koraiensis half-sib families.Growth traits assessed included height,diameter at breast height,volume,degree of stem straight-ness,stem form,and branch number per node,while wood properties assessed included density,fiber length and width,fiber length to width ratio,and cellulose,hemicel-lulose,holocellulose,lignin,and ash contents.Except for degree of stem straightness and branch number per node,all other traits exhibited highly significant variations(P<0.01)among families.The coefficients of variation ranged from 5.3(stem form)to 66.7%(ash content),whereas,the herit-ability ranged from 0.136(degree of stem straightness)to 0.962(ash content).Significant correlations were observed among growth traits and wood physicochemical properties.Principal component analysis identified four distinct groups representing growth traits,wood chemical and physical properties,and stem form traits.Multi-trait comprehensive evaluation identified three groups of elite families based on breeding objectives,including rapid growth,improved timber production for building and furniture materials,and pulpwood production.These specific families should be used to establish new plantations.

Sex effect on growth performance and marker-aided sex discrimination of seedlings of Populus deltoides

Sex has a significant effect on various traits among dioecious plants.In this analysis of the sex effect on the radial growth and wood density of numerous 20-yearold trees of Populus deltoides growing in a common garden,male trees performed better than the females in radial growth,but sex did not significantly affect wood density.Growth rate and wood density were weakly negatively correlated.Sex selection is also critical for controlling seed-hair pollution from P.deltoides plantations.However,because the juvenile period of P.deltoides lasts for years,a reliable technique to determine the sex of juveniles has been needed.Here we developed a marker-aided technique to discriminate the sexes of P.deltoides seedlings.This study provides essential information on target traits and a highly desirable genetic toolkit for accelerate breeding programs for this important tree species.

Dietary β-glucan supplementation improves growth performance,carcass traits and meat quality of finishing pigs

This experiment was conducted to investigate growth performance,carcass traits and meat quality of finishing pigs with dietary β-glucan supplementation.A total of 96 healthy pigs(Duroc x Landrace x Yorkshire;initial average BW=25 kg) were randomly allocated into 4 dietary treatments with 6 replicates per treatment and 4 pigs per replicate.The control group was fed a basal diet,and the experimental diets were supplemented with 50,100 and 200 mg/kg Agrobacterium sp.ZX09β-glucan,respectively.The experiment lasted 103 d.The basal diet supplemented with 100 mg/kg β-glucan significantly increased average daily gain and feed conversion ratio,probably due to the improved digestibility of dry matter,gross energy and crude protein(P <0.05).Beta-glucan supplementation from100 to 200 mg/kg of diet significantly increased carcass length(P <0.05).The basal diet supplemented with 100 mg/kg β-glucan supplementation also significantly(P <0.05) increased muscle pH,reduced drip losses and increased a~*values.The basal diet supplemented with 100 mg/kg β-glucan increased the content of intramuscular fat and changed the proportion of saturated fatty acid and unsaturated fatty acid,thereby improved the flavor of meat.In conclusion,the basal diet supplemented with 100 mg/kg Agrobacterium sp.ZX09 β-glucan improves growth performance,nutrient digestibility,carcass length,and pork quality of finishing pigs.

Clonal Variation in Growth and Wood Quality and the Multi-Trait Index Selection of Chinese Fir

Two clonal trial stands of Chinese Fir （Cunninghamia lanceolata） were used in this study, one was 19-year-old stand which included 38 clones, and the other was 17-year-old stand including 102 clones.The statistical analyses showed that there were very significant genetic variations in height, DBH,volume and ratio of heartwood(Rhw),wood basic density（ρb ） of the clones in the two stands. The repeatability of clones was in median to high level,and the genetic CV was different over the all five traits.There were very significant phenotypic and genetic correlations among height,DBH and volume,and negative correlations among growth, Rhw andρb.The selection method experiment indicated that index selection could improve volume, Rhw andρb,showing synthetically superior selection effects compared to any individual trait selection methods.

巴民和松巴民杂交猪生长性能、胴体和肉质性状的比较研究

本试验旨在通过测定巴克夏公猪与民猪母猪的二元杂交猪(简称巴民猪)和松辽黑猪公猪与巴民母猪的三元杂交猪(简称松巴民猪)的生长性能、胴体和肉质性状,比较分析利用地方品种、地方培育品种和引进品种进行三元杂交的优势和可行性。试验选用出生日龄相近的巴民猪200头,松巴民猪196头,用于生长性能测定;选用100 kg体重的巴民猪50头,松巴民猪45头,屠宰用于测定胴体性状和肉质性状。结果表明,松巴民猪日增重和饲粮转化率显著高于巴民猪(P<0.05),校正至100 kg日龄和校正至100 kg体重背膘厚均显著低于巴民猪(P<0.05);松巴民猪平均背膘厚和肌内脂肪含量显著低于巴民猪(P<0.05),瘦肉率显著高于巴民猪(P<0.05),其他肉质指标差异不显著(P>0.05)。综上所述,松巴民猪生长速度和饲料利用率均高于巴民猪,瘦肉率亦有所提高,肌内脂肪含量虽有所下降,但也达到了4%,保持了民猪的优良肉质特性,因此饲养松巴民三元杂交猪将具有更高的经济效益。

南方型黑杨生长性状和木材材性与湿心材形成的相关性

为了分析南方型黑杨生长性状、木材性状对其湿心材形成的影响程度,于2023年11月份,在岳阳市君山区丁字堤南方型黑杨试验林,选取13年生的8个南方型黑杨无性系为研究对象,每个无性系选取6株样株,用9 mm生长锥在树高1.3 m处钻取木样,分别测量木芯长度、湿心材长度,并称量质量;依据试验设计,测定样木的胸径、树高、材积、树液pH、生材含水量、气干材含水量、木材基本密度;运用相关分析法、通径分析法,计算各性状对湿心材比例的直接影响、间接影响、决定系数,分析南方型黑杨无性系生长性状、木材性状的7个性状指标对湿心材比例的影响。结果表明:8个无性系间,湿心材比例、胸径、树高、材积、生材含水量存在极显著差异。树液pH和生材含水量,与湿心材比例存在极显著正相关,气干材含水量与湿心材比例存在显著正相关。通径分析表明,生材含水量(W r)、树液pH、气干材含水量(W a)是影响湿心材比例(R(wh))的重要因子,通过多元回归分析建立3个性状与湿心材比例的多元回归方程R(wh)=-0.995+0.006pH+0.075 W r+0.005 W a;其中,生材含水量对湿心材比例的直接影响(0.522)和单独决定系数大小表明,生材含水量对湿心材比例影响最大。因此,生材含水量大小可以作为选育南方型黑杨低湿心材选育时的评定指标。

滇西南29年生柚木种源/家系多性状综合选择

[目的]通过对滇西南柚木种源/家系试验林早期与29年生的适应性、生长和形质性状进行综合评价,旨在为当地选出适应性强、速生、形质优良的柚木种源/家系。[方法]从国内外收集了34个柚木种源和家系,采用完全随机区组设计,(2×2)株小区,8次重复,调查、分析和比较试验林早期2~8年生与29年生的保存率和生长差异,对29年生种源/家系的保存率和优势木生长与形质性状采用主分量分析,综合评价出优良种源/家系。[结果]早期2~8年生柚木种源/家系间的保存率差异均不显著,而29年生保存率种源/家系间差异呈极显著;但2~8年生和29年生种源/家系间生长和形质性状的差异均达到极显著,2~8年生最好种源/家系的平均树高、平均胸径和平均单株材积分别是生长最差的1.38~1.91倍、1.63~2.18倍和3.82~5.17倍,而29年生最好种源优势木的平均树高、平均胸径、平均单株材积、树干通直度和主干材高分别是最差种源的1.81倍、1.87倍、4.84倍、2.18倍和12.89倍,通过优良种源/家系选择可获得较大的增产效益。29年生种源/家系的保存率和优势木生长性状与4~8年生优势木的生长性状均呈显著至极显著相关;29年生种源/家系的优势木树干通直度与优势木各生长性状、优势木主干材高与优势木的平均树高和单株材积生长相关显著至极显著。29年生种源/家系保存率、生长和形质性状主成分分析的前三个主分量累积贡献率达97.63%,根据种源/家系在前三个主分量的综合得分,按20%的入选率评选出7个优良种源/家系:种源8410、8603、8407、8602、85131、1007和家系7564#。[结论]29年生入选的7个种源/家系的优势木树高、胸径、单株材积、树干通直度和主干材高的遗传增益分别为7.92%、9.39%、14.74%、7.06%和12.29%,其中来自云南陇川林场种源8410和海南尖峰岭种源8603更适宜当地生长。

江苏省沿海低海拔湿热地区饲用藜麦不同生长时期农艺性状及营养品质研究

[目的]筛选适合在江苏省沿海低海拔湿热地区推广种植的饲用藜麦品种。[方法]以红心藜麦、蒙藜1号、SL577C、SL2860D、SL923E 5个饲用藜麦品种为试验材料,选取3个生长时期(90、105、120 d)作为观测时间,测定并比较不同品种饲用藜麦植株的农艺性状指标(株高、叶绿素含量、单株鲜重、单株叶重、单株茎重、茎叶比)和营养品质指标(干物质、粗蛋白、中性洗涤纤维、酸性洗涤纤维含量)。[结果]在3个观测时间点,红心藜麦的株高、单株鲜重、单株叶重、单株茎重均显著(P<0.05)高于其他4个饲用藜麦品种;茎叶比低于其他4个饲用藜麦品种。生长90、105、120 d时,叶绿素含量最高的品种分别为SL577C、SL2860D、蒙藜1号,三者均显著(P<0.05)高于红心藜麦;干物质含量最高的品种分别为SL577C、SL2860D、SL577C,三者均显著(P<0.05)高于红心藜麦、蒙藜1号、SL923E。生长90 d及105 d时,蒙藜1号的粗蛋白含量最高,生长120 d时,SL577C的粗蛋白含量最高,均显著(P<0.05)高于红心藜麦。生长90 d及105 d时,5个品种藜麦植株的中性洗涤纤维及酸性洗涤纤维含量之间无显著(P>0.05)差异;生长120 d时,红心藜麦的酸性洗涤纤维含量最高,显著(P<0.05)高于其他4个饲用藜麦品种。随着生长时期的推进,红心藜麦的粗蛋白含量呈下降趋势、中性洗涤纤维及酸性洗涤纤维含量呈上升趋势;在生长105 d时,蒙藜1号的干物质、粗蛋白、中性洗涤纤维及酸性洗涤纤维含量综合表现最佳;在生长120 d时,SL577C的干物质、粗蛋白、中性洗涤纤维及酸性洗涤纤维含量综合表现最佳。[结论]综合农艺性状和营养品质表现,红心藜麦、蒙藜1号、SL577C是适合在江苏省沿海低海拔湿热地区种植的饲用藜麦品种,在实际生产中,分别适宜在生长90、105、120 d左右采收。

酵母硒对肉鸡生长性能、屠宰性能、肉品质和抗氧化性能的影响

旨在探讨酵母硒对肉鸡生长性能、屠宰性能、肉品质和抗氧化性能的影响。选取150只1日龄白羽公肉鸡,随机分成5组,每组6个重复,每个重复5只,对照组以玉米-豆粕为基础饲料,各试验组Ⅰ、Ⅱ、Ⅲ、Ⅳ分别添加0.1、0.2、0.3和0.4 mg/kg的酵母硒,预试期7 d,正式试验期42 d。结果显示:添加酵母硒的各试验组对生长性能和屠宰性能均无显著影响(P>0.05)。在肉品质方面,试验Ⅲ组和试验Ⅳ组的红度(a^(*))值和宰后45 min的pH值均显著高于对照组(P<0.05);试验Ⅱ组、试验Ⅲ组、试验Ⅳ组宰后24 h的pH值与对照组相比有显著提高(P<0.05)。在抗氧化性能方面,试验Ⅳ组的超氧化物歧化酶(SOD)活性极显著高于其他各组(P<0.01),试验Ⅱ组和试验Ⅲ组的过氧化氢酶(CAT)活性显著高于对照组(P<0.05),试验Ⅲ组谷胱甘肽过氧化物酶(GSH-Px)活性极显著高于其他各组(P<0.01)。提示:肉鸡日粮添加酵母硒的最适宜添加量为0.3 mg/kg。

杉木高世代杂交子代生长与木材性状遗传分析

为揭示杉木高世代杂交子代生长与材性性状的遗传效应,选择优良的杂交组合,利用设置在浙江省开化县林场的4×5双因素交叉设计的杉木高世代杂交子代测定林,研究8年生杉木的生长性状、木材基本密度和树干碳含量,估算各性状一般配合力(GCA)/特殊配合力(SCA)效应值及相对重要性,分析遗传控制方式及性状间的相关性。结果表明:杉木树高、胸径、单株材积、木材基本密度、树干碳含量在杂交组合间均差异显著(P<0.05),含碳率在组合间差异不显著。父母本配合力分析显示,树高、胸径、单株材积、树干碳含量的母本效应均大于父本效应,C25-3母本效应最大,B109-3父本效应最大;杂交组合各性状均以加性基因效应控制为主,杉木高世代育种工作仍需注重亲本的选配。性状间相关性分析表明,树干碳含量与生长性状呈显著正相关,按10%的入选率,联合选择出3211和3215两个速生高固碳的杂交组合,单株材积较对照(CK)增加30.91%以上,树干碳含量较CK增加26.95%以上,而木材基本密度与生长性状呈弱相关或负相关,筛选出3218和3216两个木材性状优良的杂交组合,木材基本密度较CK增加2.17%以上。

不同类型生物炭对芳香樟生长及光合特性的影响

【目的】探究不同类型生物炭对芳香樟生长和光合特性的影响,以期为芳香樟经济林营造提供科学依据。【方法】以盆栽芳香樟优质品系‘MD1’为材料,设置对照(CK,不施化肥和生物炭)、化肥(F)、木炭+化肥(MC)和秸秆炭+化肥(JC)4个处理,在芳香樟移栽前一天施入生物炭(140 g/盆)、化肥(尿素、过磷酸钙、氯化钾分别为6,2.19,0.44 g/盆),将其与土壤混匀,移栽定植后浇水灌透。移栽后测定施用不同类型生物炭对芳香樟生长指标、各器官精油含量、芳樟醇相对含量和根系活力的影响,并分析叶片光合特性和氮代谢的调控过程。【结果】1)与施用化肥处理相比,不同类型生物炭处理均可提高芳香樟株高、地径、总生物量和根系活力,且不同类型生物炭处理之间差异显著,JC处理对芳香樟植株生长的促进效果优于MC处理,其芳香樟株高、地径、总生物量和根系活力比MC处理分别增加了36.22%,8.24%,8.68%和12.80%。2)与施用化肥处理相比,不同类型生物炭处理均可显著提高芳香樟茎、叶得油率和芳樟醇相对含量,其中以JC处理芳香樟叶得油率和芳樟醇相对含量最高,分别达4.05%和94.31%。3)施用生物炭可提高芳香樟SPAD值和净光合速率,蒸腾速率随时间的变化呈先升高后降低的趋势,减少光合产物消耗;化肥处理除亚硝酸还原酶外,氮代谢酶活性显著高于其他处理。【结论】施用不同类型生物炭均能促进芳香樟生长,提高精油含量和芳樟醇相对含量,改善芳香樟的光合生理特性,其中以秸秆炭+化肥处理综合表现最优。

5个贵妃鸡配套系生长发育规律、屠宰性能和肉品质比较分析

旨在筛选出生长性能好、屠宰性能优良、肉品质鲜美的贵妃鸡杂交组合,为贵妃鸡的品种改良提供科学依据。本研究选择体重接近的20周龄健康贵妃鸡为母本,与河南农业大学家禽种质资源场培育的同周龄的豫农D系、豫农L系、豫农SHj系、豫农C系和豫农H系进行杂交配套试验,杂交后代分别为D×HD、L×HD、SHj×HD、C×HD、H×HD。各组合按性别选取健康雏鸡各50只,常规饲养至12周龄,每两周固定时间测定体重,采用Logistic、Gompertz和Von Bertallanffy 3种非线性生长曲线模型对其体重进行拟合,并随机挑选各组合12周龄健康试验鸡公母各6只进行屠宰,测定其生长性能、屠宰性能以及肉品质等指标,对各指标进行生物统计学分析。结果表明:Gompertz模型的拟合结果最优,拟合度均在0.998以上;在生产性能方面,C×HD组合的平均体重和体尺指标显著高于其他组合(P<0.05)且母鸡饲料报酬最高(2.59),SHj×HD组合公鸡饲料报酬最高(2.39);在屠宰性能方面,除L×HD和H×HD组合中的母鸡之外,其它组合公母鸡均达到半净膛率70%以上,全净膛率60%以上,肉用性能良好;在肉品质方面,D×HD组合的肉质较优于其他组合,但各组合滴水损失无显著差异。基于以上结果,C×HD组合在生长性能、屠宰性能、肉品质等方面大多表现优异,可以在一定程度上满足消费者的需求。此外,研究结果也为贵妃鸡遗传资源的保护、进一步开发和品种选育提供重要参考依据,为贵妃鸡的高效养殖和推广提供了有力的支持。

毛红椿生长、心材和材性性状遗传分析及家系选择

[目的]通过研究15年生毛红椿家系试验林的生长、心材和材性性状的遗传变异规律,选择速生且优质的毛红椿优良家系。[方法]以浙江开化县林场的15年生毛红椿家系试验林为材料,测定其树高、胸径、材积、心材率、心材材积和木材基本密度,进行方差、相关和主成分等分析。[结果]毛红椿家系间树高、胸径、材积、心材率、心材材积和木材基本密度等6个生长、心材和材性性状的差异均达极显著水平,并有较高的遗传稳定性,但冠幅和枝下高在家系间差异不显著。表型相关和遗传相关分析表明,毛红椿胸径与心材材积和材积之间呈显著正相关,通过对胸径的选择能间接实现对材积和心材材积的选择。主成分分析结果显示,材积、心材材积、胸径、树高和心材率等5个性状代表了毛红椿的品质和经济性状,对前两个主成分PC1和PC2的贡献率较高。通过构建材积、心材率、心材材积和木材基本密度等4个性状的综合指数选择方程,对毛红椿所有家系进行综合评价,选出了2个符合改良条件的优良家系,其材积、心材率、心材材积和木材基本密度获得的平均遗传增益分别为:52.84%、0.49%、66.23%和2.13%。[结论]毛红椿育种目标应重点围绕生长和心材性状,而冠幅和枝下高遗传力较小且家系间差异不显著,不适宜作为遗传改良的目标。

东北地区不同间伐强度青山杨人工林生长及木材性状变异

探究不同间伐强度对青山杨人工林生长及木材性状的影响,为东北地区培育杨树优质工业资源材提供理论基础。以18年生青山杨为试验材料,以初植株行距2 m×3 m为对照,设置3种强度的间伐处理(4 m×3 m、6 m×3 m、4 m×6 m)。间伐后第5年对试验林的生长性状(树高、胸径、2米径、冠幅)及木材性状(基本密度、纤维长、纤维宽、半纤维素含量、纤维素含量、综纤维素含量、木质素含量)进行了测定,并利用树高、胸径计算出单株材积及单位面积蓄积。方差分析结果表明,除基本密度外,各指标差异均达到极显著水平(P<0.01)。均值分析结果表明,林木各生长指标与木质素含量的均值在株行距为6 m×3 m时达到最大,其余各木材指标均在株行距为4 m×3 m或6 m×4 m时达到最大;各测定指标表型变异系数变化范围为3.35%~29.87%;除基本密度外,各指标重复力均超过0.590。相关性分析结果表明,各生长指标间均达显著正相关水平(0.690<r<0.993),而木材性状间及生长性状与木材性状间的相关性较弱。分别以生长性状、木材性状及联合生长与木材性状为评价指标对各处理进行综合评价后发现,Qi分别在株行距为6 m×3 m、4 m×6 m及4 m×6 m时达到最大。间伐能够促进林分生长,改良林木材性,且保留株行距为4 m×6 m时,林木材性及生长与木材综合改良效果较为优良;保留株行距为6 m×3 m时,林木生长效果最好。因此,今后可根据培育目标的不同选择适宜的间伐强度进行东北地区杨树优质工业资源材的培育。

饲粮粗纤维水平对猪生长性能、胴体性状及肉品质的影响

【目的】探讨饲粮粗纤维(CF)水平对育肥期马身猪和杜洛克猪×长白猪×大白猪(杜长大猪)生长性能、胴体性状及肉品质的影响,为猪精准营养需要量构建和优质猪肉的生产提供理论依据。【方法】选取体重为(49.67±5.85) kg的健康马身猪和杜长大猪各80头,品种内随机分为4组,每组5个重复,每个重复4头猪,各组猪分别饲喂粗纤维水平为2%、5%、8%和11%的饲粮,分别记为2%CF、5%CF、8%CF、11%CF组。预试期7 d,正试期30 d。试验结束后,每个处理挑选体重接近平均值的3头猪屠宰,测定胴体性状和肉品质指标。【结果】饲粮粗纤维水平显著影响猪的生长性能,其中11%CF组马身猪平均日增重显著低于其他3组(P<0.05),11%CF组杜长大猪料重比显著高于其他3组(P<0.05)。饲粮粗纤维水平对猪的背膘厚、眼肌面积和后腿比例等胴体性状有显著影响,其中2%CF组马身猪背膘厚显著高于其他3组(P<0.05),11%CF组杜长大猪背膘厚显著低于其他3组(P<0.05);随着粗纤维水平的提高,眼肌面积呈逐渐增大趋势,在马身猪和杜长大猪中均表现为11%CF组的眼肌面积极显著高于其他3组(P<0.01),8%CF组显著高于2%CF和5%CF组(P<0.05);5%CF和8%CF组马身猪后腿比例显著高于其他2组(P<0.05)。饲粮粗纤维水平对猪肉品质有显著影响,其中2%和5%CF组马身猪肌内脂肪含量极显著高于其他2组(P<0.01);5%CF组马身猪胱氨酸含量显著高于其他3组(P<0.05),2%CF组蛋氨酸含量显著低于其他3组(P<0.05);8%CF组马身猪棕榈酸、硬脂酸、油酸和亚油酸含量均为最高,而杜长大猪的变化趋势则相反。【结论】马身猪在饲喂8%粗纤维水平饲粮时,饲料转化率升高,背膘厚降低,眼肌面积增大,肉色得到改善;杜长大猪在饲喂5%粗纤维水平饲粮时,日增重增加,饲料转化率提高,眼肌面积增大,胴体性状和肌肉嫩度较好。

生长和木材性状耦合评价红松半同胞家系

红松(Pinus koraiensis)是东北地区重要的果材兼用树种,但由于生长周期长,遗传改良进展缓慢,为评价和筛选优质红松种质资源,以吉林省永吉县西阳林木种子园内36个20年生红松半同胞家系为材料,对其生长性状和木材性状进行测定。方差分析结果表明,各性状在家系间差异均达显著水平(P<0.01),各性状表型变异系数为5.89%~45.21%;除通直度(0.46)外,其他性状的家系遗传力均超过0.5,属于高遗传力。相关分析结果表明,树高、胸径等生长性状间均达极显著正相关水平(r>0.663),木材性状间半纤维素、纤维素和综纤维素含量间达显著相关水平,而生长性状与木材性状间仅纤维素含量、综纤维素含量与部分生长性状呈显著负相关。主成分分析结果表明,14个性状构成5个主成分,累计贡献率为79.24%。利用综合评价法对36个半同胞家系进行评价,以10%的入选率,依据生长性状,初步筛选3个优良家系(家系PK61、PK29和PK22),各生长性状遗传增益为6.41%~33.91%;依据木材性状,初步筛选3个优良家系(家系PK16、PK78和PK10),各木材性状遗传增益为1.08%~6.72%;结合生长和木材性状初步筛选出3个优良家系(家系PK61、PK29和PK44),各指标遗传增益为0.27%~37.28%。该研究选出的优良家系可为红松良种选用提供基础。