纤维素组合酶在不同品种生长猪饲粮中的适宜添加量

本试验利用体外消化试验筛选出3种纤维素酶的最优组合,采用消化代谢试验来确定所筛选的纤维素组合酶在2个品种猪纤维性饲粮中的适宜添加量.试验以酸性洗涤纤维(ADF)为评定指标,以地瓜蔓为粗纤维来源,配制3.8％ ADF和5.8％ ADF的2种纤维水平的饲粮.分别选取5头体重[(25±1) kg]相近、健康去势的烟台黑猪和杜×鲁烟白杂交猪,于回肠末端安装T型瘘管,设5个最优纤维素组合酶添加量:0(对照组)、0.05％、0.10％、0.15％、0.20％,采用5×5拉丁方设计进行消化代谢试验.结果表明:在5.8％ ADF水平饲粮中,与对照组相比,纤维素组合酶添加量分别为0.10％和0.15％时,对2个品种猪养分消化率以及氮平衡的影响达到了显著水平(P＜0.05),但在3.8％ ADF水平饲粮中差异不显著(P＞0.05).在5.8％ ADF水平饲粮中,在纤维素组合酶添加量相同的情况下,对于必需氨基酸,蛋氨酸、缬氨酸、异亮氨酸、苯丙氨酸的回肠表观消化率烟台黑猪极显著高于杜×鲁烟白杂交猪(P＜0.01);对于非必需氨基酸,除丝氨酸和甘氨酸回肠表观消化率差异不显著(P＞0.05)外,其他氨基酸回肠表观消化率差异极显著(P＜0.01).结果提示,在5.8％ ADF水平饲粮中,烟台黑猪纤维素组合酶适宜添加量为0.10％,杜×鲁烟白杂交猪为0.15％.     

A combination of Lactobacillus buchneri and Pediococcus pentosaceus extended the aerobic stability of conventional and brown midrib mutants–corn hybrids ensiled at low dry matter concentrations by causing a major shift in their bacterial and fungal community

We evaluated the effects of applying a combination inoculant to four corn hybrids harvested at high moisture on their nutritive value and microbial populations. The treatment design was the factorial combination of corn hybrids ensiled with (INO) and without (CON) inoculant. The hybrids were TMF2R737 (MCN), F2F817 (MBR), P2089YHR (PCN), and PI144XR (PBR), ensiled at dry matter (DM) concentrations of 30.5%, 26.3%, 31.1%, and 31.5%, respectively; MBR and PBR were brown midrib mutants (BMR). The inoculant contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 10⁵ and 1 × 10⁵ cfu/g of fresh corn). The experiment had a complete randomized design with treatments replicated six times. Corn was treated or not with inoculant, packed into 7.6 L bucket silos, and stored for 100 d. At d 0, the relative abundance (RA, %) of Enterobacteriaceae was lower in PBR vs. the other hybrids [51.3 vs. x¯ = (average of) 58.4] and in the case of fungi, incertae sedis (i.s.) Tremellales and Mucoraceae were more and less abundant, respectively, in conventional hybrids vs. BMRs (x¯= 25.8 vs. x¯ = 13.9 and x¯ = 3.64 vs. x¯ = 7.52; P < 0.04). After ensiling, INO had higher LAB (9.3 vs. 7.1 log cfu/g of fresh corn) and acetic acid (3.44% vs. 1.32% of DM) and lower yeast (3.1 vs. 4.6) and molds (1.5 vs. 3.0), and also extended the aerobic stability (582 vs. 111 h) but decreased DM recovery (95.6% vs. 97.4%) vs. CON (P < 0.02). Inoculation reduced bacterial phylogenetic diversity (6.75 vs. 14.4) but increased fungal observed taxonomical units (46 vs. 20) vs. CON (P < 0.01). Also, a higher relative abundance (RA) for Lactobacillaceae (99.2% vs. 75.7%) and lower for Enterobacteriaceae (0.28 vs. 9.93) was observed due to inoculation (P < 0.001). For fungi, INO had a lower RA compared to CON for Monascaceae (12.6 vs. 44.7) and increased i.s. Tremellales (8.0 vs. 1.2) and i.s. Saccharomycetales (6.4% vs. 0.3%; P < 0.006). Inoculation changed the diverse bacterial community found in the phyllosphere across hybrids to a taxonomically uneven one dominated by Lactobacillaceae. In the case of fungi, INO application increased the fungal diversity at d 100 mainly by reducing the dominance of Monascaceae vs. CON. In conclusion, the INO treatment overwhelmed the disparate microbial populations found across BMR and conventional hybrids ensiled at low DM concentrations and ensured a significant concentration of acetic acid that modified fungal populations and in turn extended the aerobic stability of all hybrids.     

“假黄牛”或“假牦牛”精母细胞减数分裂及精子发生的研究

黄牛与牦牛种间杂交的F3代杂种公牛,精母细胞减数分裂及精子发生的水平,与F1和F2代相比,呈现明显的渐进性改善。但个体间睾丸发育状况及减数分裂与精子发生水平仍有较大差异,且仍能观察到一些异常现象。F3代公牛虽能产生数量较多的精子,但大多仍是畸形或有缺损,这可能是其仍无生育力的主要原因。     

高加索三叶草×白三叶胚萌发条件的探索

以六倍体高加索三叶草Trifolium ambiguum与四倍体白三叶T.repens为亲本,通过远缘杂交,采用组织培养手段对杂交胚的萌发条件进行探索.结果表明:以高加索三叶草为母本、白三叶为父本,在花期8:00-9:00授粉,授粉后12～13 d取胚,用质量分数10%NaClO灭菌6.5～7 min,在不加任何外源激素的改良MS培养基上,胚萌发率最高,达8%.高频扩繁时,再附加0.25 mg/L 2,4-D+0.50 mg/L 6-BA可获得较高萌发率.     

南瓜新品种科栗1号的选育

科栗1号是以S31-1为母本、S4-1为父本配制而成的南瓜一代杂种。植株蔓生,长势中等;分枝较少,叶小,节间短;第1雌花节位第9节左右;嫩瓜扁圆形,瓜皮绿色覆绿色斑点和浅色纵条斑纹,老瓜皮墨绿色。嫩瓜单瓜质量0.5~1.5kg,果实横径9cm左右,纵径13cm左右,糯性好,粉质,品质佳;春季露地和秋季设施栽培嫩瓜产量1500~2000kg·(667m2)-1,早春设施栽培嫩瓜产量3000kg·(667m2)-1左右。适宜浙江省及栽培条件相似的地区推广种植。     

秋冬萝卜新品种晋萝卜4 号的选育

晋萝卜4 号是以雄性不育系4-01A 为母本，自交系03-37-1 为父本配制而成的秋冬萝卜一代杂种，生育期80 d（天）。地上部叶丛半直立，叶片稀疏，肉质根圆柱形，表皮光滑，出土部分皮绿色，入土部分皮白色，近1/2 露出地面。含水量适中，肉质甜脆，商品性好。肉质根纵径30 cm，横径7～8 cm，单根质量1.5 kg，每667 m² 产量5 000 kg 左右。适宜山西省及其周边地区种植。     

水果萝卜新品种京脆1 号的选育

京脆1 号是由两个自交不亲和系05132 和05177 配制而成的鲜食水果型萝卜一代杂种。生长期75～80 d（天），叶
片近板叶型，深绿色，半直立株型。肉质根椭圆形，尾根细，茎盘小。根长13 cm，横径12 cm，平均单根质量1.2 kg，每
667 m² 产量5 000～6 000 kg。肉质根3/4 露出地面，出土部分浅绿色，入土部分白色，肉色浅绿，肉质甜脆，VC 含量 380
mg·kg^-1（FW），硫苷含量318.8 μmol·kg^-1（FW），适合生食。田间对病毒病和软腐病的抗性强于对照满堂红。适合北京、
天津、河北、山东等地种植。     

茄子新品种京茄13号的选育

京茄13号是以优良自交系1156为母本,以1125为父本配制而成的长茄一代杂种。早熟,始花节位为第10节,植株长势强,节间短。果实顺直,长筒状,果长25~30cm,横径5~6cm,果皮黑亮,连续坐果性强,每667m2平均产量为4240kg,低温耐受性强,适合北方保护地栽培。     

薄皮甜瓜新品种京玉绿宝的选育

京玉绿宝是以白沙蜜5代自交系357为母本,以地方品种240提纯系选后代397为父本配制而成的薄皮甜瓜一代杂种。果实扁卵圆形,单果质量200~400g,果面光滑无棱,果皮深绿色,果肉白绿色,可溶性固形物含量11%~15%,早熟,抗逆性较强,适合保护地及少雨露地栽培,每667m2产量1600kg。已在北京、河北、辽宁、吉林、内蒙古等地示范推广3000hm2。     

瓠瓜新品种浙蒲8号的选育

浙蒲8号是以自交系G7-4-3-1-2-1为母本、自交系J63-1-6-3-2-1为父本配制而成的耐热瓠瓜一代杂种。植株生长势较强,早中熟,以侧蔓结瓜为主,坐瓜性较好。商品瓜中棒形,上下粗细较均匀,平均瓜长约30cm,横径约5cm,瓜皮绿色,具光泽,单瓜质量0.4~0.5kg。耐高温性较强,高温期商品瓜率较对照杭州长瓜高6个百分点;品质佳,游离氨基酸总量1304.193μg·g-1,其中谷氨酸含量85.663μg·g-1;田间对枯萎病和白粉病的抗性强于对照杭州长瓜。适宜作露地栽培和夏秋季设施避雨栽培,夏秋季栽培每667m2产量2600kg以上。