Identification of candidate genes for early-maturity traits by combining BSA-seq and QTL mapping in upland cotton(Gossypium hirsutum L.)

Cotton breeding for the development of early-maturing varieties is an effective way to improve multiple cropping indexes and alleviate the conflict between grains and cotton in the cultivated fields in China.In the present study,we aimed to identify upland cotton quantitative trait loci(QTLs)and candidate genes related to early-maturity traits,including whole growth period(WGP),flowering timing(FT),node of the first fruiting branch(NFFB),height of the node of the first fruiting branch(HNFFB),and plant height(PH).An early-maturing variety,CCRI50,and a latematuring variety,Guoxinmian 11,were crossed to obtain biparental populations.These populations were used to map QTLs for the early-maturity traits for two years(2020 and 2021).With BSA-seq analysis based on the data of population 2020,the candidate regions related to early maturity were found to be located on chromosome D03.We then developed 22 polymorphic insertions or deletions(InDel)markers to further narrow down the candidate regions,resulting in the detection of five and four QTLs in the 2020 and 2021 populations,respectively.According to the results of QTL mapping,two candidate regions(InDel_G286-InDel_G144 and InDel_G24-InDel_G43)were detected.In these regions,three genes(GH_D03G0451,GH_D03G0649,and GH_D03G1180)have nonsynonymous mutations in their exons and one gene(GH_D03G0450)has SNP variations in the upstream sequence between CCRI50 and Guoxinmian 11.These four genes also showed dominant expression in the floral organs.The expression levels of GH_D03G0451,GH_D03G0649 and GH_D03G1180 were significantly higher in CCRI50 than in Guoxinmian 11 during the bud differentiation stages,while GH_D03G0450 showed the opposite trend.Further functional verification of GH_D03G0451 indicated that the GH_D03G0451-silenced plants showed a delay in the flowering time.The results suggest that these are the candidate genes for cotton early maturity,and they may be used for breeding early-maturity cotton varieties.

Yield Stability of Direct-sowing and Early-maturing Excellent Brassica napus (Attar No.8)

[Objective] The aim was to analyze yield stability of attar No.8, which is direct sowing and early-maturing. [Method] Analysis was made on yielding ability, stability and adaptability of attar No.8 in Yunnan Province during 2006-2009 with DPS software and stability assessment was conducted on yield and major economic characters of the variety in different periods and experimental plots. [Result] Average yield of attar No.8 during three years in 24 plots achieved 3 379.17 kg/hm2; it grew tightly and is featured with early matureness. In addition, grain density, pod number and annul production differed little in different years and the variety in eight ecological conditions all showed high production potential, yielding ability and stability, which proved that attar No.8 is suitable to be grown in Yunnan and southern early-maturing areas in China. [Conclusion] The research provided references for selection and breeding of rapeseeds＇ variety which enjoys high and stable yield.

Influence of the Number of Reserved Fruit on Fruit-bearing Branch of Early-maturing Citrus unshiu Marc. on Fruit Growth and Development

In order to provide theoretical references for early-maturing Citrus unshiu Marc. in terms of fruit thinning, timely fertilization and harvesting, as wel as for for-mulation of of Early-maturing Citrus unshiu Marc. Cultivation Technique Standards in Guizhou Province, the dynamic changes of fruit longitudinal diameter and trans-verse diameter of 11-year-old and 12-year-old early maturing Citrus unshiu Marc. were tested in two consecutive years and the effects of single-fruit bearing branch on fruit growth and development were compared. The results showed annual varia-tion of longitudinal and transverse diameter of the fruit in Guizhou grew faster at the beginning and then slowed down gradual y, maintaining a slow-growth period after October; the growth curve final y was flat in mature stage. General y, the growth and development stage of fruit showed four growth peaks, showing an in-creasing S-shape curve and fruit net increase also had four growth peaks with a double S-shape curve. Specifical y, longitudinal diameters growth alternated with transverse diameter growth and the former proved much stronger. In terms of ef-fects of single-fruit bearing branch on longitudinal and transverse diameter growth, the number of reserved fruits had direct effects on the growth, net increase of weight, time of growth peak, fluctuation and the number of growth peak. The growth and development, and quality of fruits in the treatments with two or three fruits re-served on single fruit-bearing branch proved better compared with the control with four left fruits. It suggested that early June and early July are the best time for fer-tilization of early-maturing Citrus unshiu Marc. in Guizhou Pprovince and would have better effect if combined with foliage spraying. The suitable harvest time is in the end of October. The preferred number of reserved fruit on single fruit-bearing branch is 2-3. In actual production, the implementation of flower and fruit thinning should also takes tree age, balance of tree vigor, strength of fruit bearing branch, alternate bearing phenomenon and other factors into consideration.

Evaluation of Different Substrates Compositions for Acclimatization of Tissue Culture Taro Plantlets in a Propagator

Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.

干旱胁迫对芋球茎淀粉和蔗糖代谢通路相关基因表达的影响

[目的]探究芋球茎响应干旱胁迫的分子机制,特别是干旱胁迫对淀粉和蔗糖代谢通路相关基因表达的影响,为耐旱品种选育提供依据。[方法]以荔浦芋1号为试验材料,对干旱胁迫下的芋球茎进行转录组测序,对获得的差异表达基因进行GO和KEGG富集分析,进一步筛选与淀粉和蔗糖代谢通路相关的酶基因,并分析这些酶基因在干旱胁迫下的表达模式。[结果]芋球茎在干旱胁迫下筛选到差异表达基因1983个,其中上调表达基因373个,下调表达基因1610个。GO富集分析显示,差异表达基因在生物过程富集最多的是细胞过程和代谢过程,在细胞组分富集最多的是细胞解剖实体,在分子功能富集最多的催化活性和结合。KEGG富集分析显示,富集最多的通路分别是代谢通路、氮素代谢通路、抗坏血酸和醛酸代谢通路。对淀粉和蔗糖代谢通路的差异表达基因进行统计,共筛选到26个差异表达基因,涉及11种酶,其中上调表达基因5个,下调表达基因21个。在干旱胁迫下,淀粉合成酶、己糖激酶、果糖激酶、UTP-葡萄糖-1-磷酸盐尿苷酸转移酶、α-淀粉酶、内切葡聚糖酶、β-葡萄糖苷酶和β-呋喃果糖苷酶的基因下调表达;UDP-葡萄糖磷酸水解酶和海藻-6-磷酸合成/磷酸酶的基因上调表达;蔗糖合成酶和β-呋喃果糖苷酶的基因既有上调表达,也有下调表达。[结论]淀粉和蔗糖代谢通路相关基因的表达受到干旱胁迫的影响。调控淀粉代谢和海藻糖生物合成相关基因下调表达,而调控蔗糖代谢相关基因既有上调表达,也有下调表达。

壳寡糖浸种对低温下江西铅山红芽芋脱毒试管芋萌发及生理代谢的影响

江西铅山红芽芋脱毒试管芋一般在1月至2月上旬晴天播种,“倒春寒”等低温胁迫会导致早播的江西铅山红芽芋脱毒试管芋生长缓慢,出苗周期变长,严重时会造成烂种死亡,出苗率降低,影响其产量。为提高播种期江西铅山红芽芋脱毒试管芋抗寒性,该研究利用植物组织培养和植物生理学的方法测定了壳寡糖浸种后低温下江西铅山红芽芋脱毒试管芋的萌发及其相关生理指标。结果表明:200~250 mg/L壳寡糖浸种可显著促进低温下江西铅山红芽芋脱毒试管芋的萌发。与低温对照相比,当浸种浓度为200 mg/L时,在内源激素方面,有利于低温下江西铅山红芽芋脱毒试管芋萌发过程中赤霉素、玉米素核苷、多胺和茉莉酸的积累,而不利于生长素和脱落酸的积累;在抗氧化方面,提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,降低了丙二醛和过氧化氢的含量;在渗透调节方面,有利于可溶性糖、可溶性蛋白、脯氨酸的积累;在代谢关键酶方面,可提高脂肪酶、蛋白酶和α-淀粉酶活性以及三磷酸腺苷含量。因此,200 mg/L壳寡糖可以调控低温下江西铅山红芽芋脱毒试管芋内源植物激素和渗透调节物质含量、抗氧化酶和代谢关键酶活性,促进其在低温下的萌发。

含紫薯花青素的槟榔芋淀粉薄膜性能及其应用

开发含紫薯花青素(PSPA)并可生物降解的槟榔芋淀粉薄膜(TSF),并研究其光学性能、厚度、含水率、水溶性、颜色、总酚含量、抗氧化活性、红外光谱和微观结构等性能,初步探讨TSF对鲜切莴笋、鱼肉和猪肉储存过程中新鲜度的指示作用。研究表明TSF的紫外-可见光谱和PSPA溶液的光谱变化规律是一致的,表明PSPA与槟榔芋淀粉具有良好的成膜机制。TSF厚度适中,含水率为39.17%,水溶性为36.93%;TSF的DPPH清除率达到94%,表明TSF的抗氧化活性高。将TSF应用于鲜切莴笋、鱼肉和猪肉的新鲜度监测,TSF先呈现淡紫色,随着时间推移,鲜切莴笋、鱼肉和猪肉逐渐腐败变质,48 h后,TSF在莴笋中呈现蓝紫色、猪肉中呈现浅绿色、鱼肉中呈现淡黄色。

紫薯香芋果冻的研制

以优质的紫薯和香芋为主要原料,经调配、混合熬煮、过滤、杀菌等工艺流程,研制出一种具有浓郁紫薯味和香芋味的果冻。以感官评价为评分标准,分析紫薯汁与香芋汁的配比,白砂糖、柠檬酸及复配胶的添加量对果冻品质的影响。通过正交试验确定紫薯香芋果冻的最佳配方。结果表明,影响果冻感官品质因素的主次顺序为柠檬酸添加量、紫薯汁与香芋汁的配比、白砂糖添加量、复配胶添加量,并且紫薯香芋果冻的最优配方为紫薯汁与香芋汁的配比1∶1,白砂糖9%,柠檬酸0.2%,复配胶1.5%。经此配方制出的果冻色泽均匀一致、口感爽滑、酸甜可口、细腻柔软,感官评分为86.6分,pH值为4.04,可溶性固形物含量为15.28%。

L-抗坏血酸联合超声处理对鲜切芋艿贮藏品质的影响

为探究L-抗坏血酸(L-ascorbic acid,AA)联合超声(ultrasound,US)(AS)处理对鲜切芋艿片贮藏品质的影响,本实验以永定六月红芋为材料,采用质量分数为2%的AA溶液浸泡15 min后,进行US(53 kHz、400 W、10 min)处理,测定贮藏期间鲜切芋艿感官品质及褐变相关酶等指标。结果表明:与对照组相比,AS处理可以降低鲜切芋艿的失水率,维持较高的硬度,延缓褐变指数升高,降低细胞膜通透性,抑制丙二醛含量累积,抑制表面微生物繁殖,从而维持鲜切芋艿较高的感官品质;与对照组相比,贮藏期间AS处理组还能维持较高的过氧化氢酶、超氧化物歧化酶活性,降低过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶活性,抑制酚类物质消耗速率,并减缓淀粉、可溶性蛋白、可溶性固形物等营养物质的流失速率,抑制可溶性醌的积累,延缓风味劣变。上述结果表明,AS处理能够保持鲜切芋艿较好的贮藏品质。

L-抗坏血酸联合超声处理鲜切芋艿的最佳条件

【目的】确定L-抗坏血酸(L-ascorbic acid,AA)联合超声(ultrasound,US)处理鲜切‘六月红芋’的最佳条件,并探究其保鲜效果。【方法】以永定‘六月红芋’为试材,通过对比自来水、纯水、去离子水、9%蔗糖溶液、1%碳酸钠溶液、1%氯化钠溶液、1%AA溶液以及不同有效氯质量浓度(20、40、60、80 mg/L)的微酸性电解水等11种保鲜护色液,筛选出对鲜切‘六月红芋’保鲜效果最佳的护色液。随后,进行AA与乙醇复配液处理,实验结果显示,AA单独使用的保鲜效果更佳。通过测定褐变度、硬度、pH值、相对电导率及感官评价得分等指标,进一步深入研究AA与US联合(AS)处理对鲜切‘六月红芋’贮藏品质的影响,以明确AS处理对鲜切‘六月红芋’的保鲜效果。【结果】在AA浓度为2%、浸泡时间为15 min、US处理时间为10 min、US频率为53 kHz、US功率为400 W的条件下,鲜切‘六月红芋’的感官品质最好。AS处理有效抑制褐变度的增加,维持酸度稳定性,减缓硬度的下降,保持细胞膜的完整性和较高的感官评分,这些参数为AS处理鲜切‘六月红芋’的最佳条件。【结论】在不同浸泡液中筛选得到AA为最佳护色液,并确定AS处理鲜切芋艿的最佳条件。AS处理能够显著提高鲜切‘六月红芋’的保鲜效果。

多维度解析干燥方式对荔浦芋品质特性的影响

【目的】从多维度解析不同干燥方式处理的荔浦芋品质差异性,为定向筛选荔浦芋的干燥加工方式提供理论依据。【方法】以条状和片状的荔浦芋为试材,采用热风干燥、热泵干燥、真空冷冻干燥和微波干燥4种干燥方式进行处理,对其品质特性、流变特性及微观结构进行测定,比较不同干燥方式的干燥效果差异。【结果】微波干燥处理的条状荔浦芋多糖含量最高,为1.178%,片状则表现为真空冷冻干燥处理的多糖含量最高,为0.976%,且真空冷冻干燥方式对不同物料形态多糖的含量影响小;不同干燥方式处理荔浦芋条、片的含水量和支链淀粉含量变化趋势一致,以真空冷冻干燥处理的芋头含水量和支链淀粉含量最低,其中芋头片含水量和支链淀粉含量分别为4.455%和1.920 mg/g,芋头条分别为3.395%和2.338 mg/g。4种干燥方式处理下的荔浦芋体系均表现为典型的剪切稀化行为,同一剪切速率下表观黏度和剪切应力均区别明显,从大到小依次为微波干燥>真空冷冻干燥>热泵干燥>热风干燥;条状芋头的表观黏度总体随多糖含量的增加而增加。真空冷冻干燥处理下的荔浦芋全粉微观上表现为光滑、完整的球状颗粒,而其他3种干燥方式处理的全粉在结构上均出现不同程度的破损、塌陷。【结论】真空冷冻干燥处理的荔浦芋含水量和支链淀粉含量低,且能最好地维持荔浦芋样品原始形状,干燥效果最优。

响应面法优化芋头豆腐酿馅料配方及其保鲜研究

以猪肉和芋头为主要原料制作豆腐酿。以感官评分为指标,在单因素试验的基础上通过响应面法优化豆腐酿的馅料配方,并进行保鲜试验。结果表明:豆腐酿馅料的最优配方为以猪肉和芋头总质量为基准,芋头添加量49.6%、食盐添加量1.0%、淀粉添加量1.6%、葱花添加量1%、蚝油添加量1%、生抽添加量1.5%、鸡蛋液添加量10%、香菇添加量2%。在4℃条件下冷藏,采用真空包装方式,乳酸链球菌素添加量为0.5 g/kg的豆腐酿馅料的保鲜期可达8 d。

Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

韶关市典型香芋产区土壤养分状况及肥力评价

【目的】了解广东省韶关市典型香芋产区的土壤肥力情况,以期为香芋产区土壤养分资源管理提供参考依据。【方法】分别于韶关市的3个香芋种植区(桂头镇老均村,廊田镇官坡滩村、农庄村)采集0~30 cm香芋根际土壤样品,测定土壤理化性质,通过主成分分析和相关性分析,筛选出最能代表当地土壤肥力的指标进入最小数据集,通过隶属度函数对所有的指标进行归一化处理,计算土壤质量指数并评价土壤肥力。【结果】3个香芋产区土壤均呈酸性;容重为1.17 g·cm^(−3),质地适宜;阳离子交换量(Cation exchange capacity,CEC)为9.17 cmol·kg^(−1),处于较低水平;速效P(54.20 mg·kg^(−1))、有效Cu(2.07 mg·kg^(−1))、有效Fe(186.33 mg·kg^(−1))、有效Zn(1.87 mg·kg^(−1))丰富,有效Mn(4.21 mg·kg^(−1))、有效B(0.12 mg·kg^(−1))、有效Mo(0.10 mg·kg^(−1))缺乏或极缺乏,其他养分含量处于中等及以上水平。3个香芋产区土壤粒级占比、碱解N、交换性Ca及交换性Mg含量差异显著,其他指标差异均不显著。从20个指标中筛选出7个指标构成土壤质量评价的最小数据集,分别为碱解N、砂粒、黏粒、交换性Ca、有效B和有效Fe含量以及CEC。评价结果表明,3个香芋产区的土壤肥力均处于中等水平,其中,碱解N和交换性Ca含量为肥力水平的主要限制因子。【结论】韶关市典型香芋产区的土壤肥力水平整体处于中等水平,土壤保肥能力较差,有效Mn、B、Mo等微量元素缺乏。因此,在香芋种植时,要注重有机肥以及微量元素肥料的施用,平衡施肥,改善土壤理化性质,提高土壤保肥能力。

真空包装结合低温贮藏对鲜切芋头的保鲜效果

鲜切芋头即使贮藏在低温条件下,切面也会出现变黄变褐的症状,导致商品性降低。为明确真空包装结合低温贮藏对鲜切芋头的保鲜效果,研究了低温贮藏条件下真空包装处理对鲜切芋头褐变和微生物总数的影响。结果表明:在低温贮藏条件下真空包装(VP)处理抑制了切面L的下降,抑制a、b、色差(△E)和褐变指数(BI)的增加,表明VP处理能显著抑制鲜切芋头褐变。VP处理有效控制微生物的生长和繁殖,在12 d时细菌总数降低了94.31%,酵母总数降低了65.02%,表明VP结合低温贮藏对鲜切芋头具有很好的保鲜效果。VP处理降低了鲜切芋头PAL和PPO活性,降低了总酚、总黄酮和总可溶性醌含量,表明VP通过减少酚类物质的合成和氧化抑制鲜切芋头褐变。VP处理抑制CAT活性的下降,提高贮藏前期的POD活性,降低LOX活性、H2O2和MDA含量,表明VP处理通过保持鲜切芋头的抗氧化活性,延缓低温贮藏期间的品质劣变。本研究证实真空包装结合低温贮藏是一种保鲜效果好、简单易用的物理保鲜技术,为真空包装在鲜切芋头保鲜中的应用奠定了基础。

低GI芋圆干的研制

以香芋为主要原料,制备低血糖生成指数(glycemic index,GI)芋圆干。通过研究白芸豆粉、燕麦粉、荞麦粉3种低GI原料对芋圆干感官评分的影响,筛选出最佳低GI原料。在单因素试验的基础上,以GI、弹性、复水比和感官评分为指标,通过正交试验优化低GI芋圆干的配方及熟化工艺。结果表明:最佳配方为以芋泥质量为基准,白芸豆粉、木薯淀粉、水、白糖添加量分别为12%、75%、22%、20%;最佳熟化工艺参数为芋圆直径1.0 cm、水煮时间2.5 min、料液比1∶35(g/mL)。在此条件下制出的芋圆干GI为53.97,感官评分为81.36。

不同红芽芋地方品种新鲜子芋自然富集元素能力的鉴定与评价

【目的】红芽芋为典型的多子芋类型,品质风味居芋类之首,是老幼皆宜和药食兼优的滋补佳品。阐明红芽芋子芋自然富集元素能力的基因型间差异,筛选出高富集有益元素且低富集有害元素的地方品种,为高产优质营养安全红芽芋地方品种的遗传改良和品种选择提供理论依据及实践指导。【方法】以21个在不同原产地广泛种植的红芽芋地方品种为材料,统一种植在同一块大田,采用电感耦合等离子体质谱法分析其新鲜子芋中有益元素[镁(Mg)、铁(Fe)、锌(Zn)、硒(Se)]和有害元素[镉(Cd)、铬(Cr)、铅(Pb)、汞(Hg)和砷(As)]的含量及累积量,并利用模糊隶属函数法、熵权优劣解距离法和模糊综合评判法对其自然富集元素能力进行综合鉴定与评价。【结果】不同红芽芋地方品种的新鲜子芋产量存在巨大差异,最高的HY09(浙江嘉兴)为最低的HY10(云南昆明)的4.5倍。不同红芽芋地方品种新鲜子芋自然富集元素能力(含量及累积量)存在明显差异,无论是同一红芽芋地方品种新鲜子芋的不同有益和有害元素含量及累积量间还是不同红芽芋地方品种新鲜子芋的同一有益和有害元素含量及累积量间均存在显著或极显著差异。有益元素中,以镁含量及累积量最高,其次为铁和锌,硒极低;但品种间的锌含量及累积量的差异最大,铁和硒次之,镁差异最小。有害元素中,以镉含量及累积量最高,汞最低,铬的品种间差异最大,砷的品种间差异最小。红芽芋地方品种对Cd的富集能力较强,对Mg的富集中等,对其他元素的富集能力极小。红芽芋新鲜子芋中的Se与Fe、Cr、Hg和As,Fe与Zn、Cr、Hg和As,Zn与Cr、Hg和As,Mg与Cd,Cr与As和Hg及Hg与As间的含量及累积量间均呈极显著正相关。【结论】综合分析显示,不同红芽芋新鲜子芋天然富集元素能力的可分为高、中和低三类,高富集能力的品种是HY14(湖南永州),中等富集能力的品种是HY04(江苏无锡)和HY20(江西赣州),其他均为低富集能力品种。

苏北地区光伏设施地芋头生长发育特点研究

芋头是江苏省特色经济作物,在苏北地区种植规模逐渐扩大,但是在光伏芋头种植方面的研究仍未见报道。本试验在光伏板间空地种植绿芽芋,与常规露地种植芋头的生长发育、产品产量、成本效益及光温环境因素进行对比。结果显示,苏北地区光伏阵列板间可进行芋头种植,芋头出苗率较高,营养体长势较强,可明显提高单株子孙芋个数和单位产量,经济效益较好。因此,苏北地区发展光伏芋头产业具有较好的推广价值和应用前景。

甘薯和芋头在闽东山羊瘤胃中的降解特性及表面附着微生物群落变化

本试验旨在研究甘薯和芋头在闽东山羊瘤胃中的降解特性及表面附着微生物群落动态变化。选用4头14月龄健康装有永久瘤胃瘘管的闽东公山羊[平均体重(26.60±2.35)kg],采用尼龙袋法分别在2、4、8、16、24、36和48 h测定甘薯和芋头的营养成分的动态降解率及降解过程中表面附着微生物变化。结果表明:1)甘薯和芋头的瘤胃降解率随滞留时间的延长均逐渐升高。干物质(DM)有效降解率分别为66.48%和62.88%,粗蛋白(CP)有效降解率分别为34.28%和32.62%,淀粉有效降解率分别为53.44%和43.60%,其中甘薯淀粉有效降解率显著高于芋头(P<0.05)。2)alpha及beta多样性结果表明,甘薯和芋头在不同滞留时间点对瘤胃细菌的丰富度、多样性和组成无显著影响(P>0.05)。门水平上,两组间优势菌均为拟杆菌门和厚壁菌门。属水平上,两组间优势菌属均为普雷沃氏菌属。Mantel检验进一步表明,假丁酸弧菌属与甘薯和芋头瘤胃降解率均呈显著正相关(r>0,P<0.05)。3)功能预测分析表明,甘薯和芋头通过磷酸戊糖途径、乙醛酸和二羧酸代谢以及丙酸代谢调控瘤胃微生物相互作用利用淀粉的功能。综上所述,甘薯和芋头具有较好的瘤胃降解性能,其中甘薯DM和淀粉降解率更佳。在降解过程中,两种饲料均不会破坏瘤胃微生物的动态平衡,因此甘薯和芋头是具有潜力的精饲料资源。

芋头粉对低盐巴沙鱼鱼糜凝胶特性的影响

为改善低盐巴沙鱼鱼糜的凝胶品质,分析芋头粉添加量对鱼糜凝胶蒸煮得率、保水性、色泽、质构的影响,并通过分析微观结构和蛋白质二级结构,探究其对鱼糜蛋白结构的影响。结果表明,当芋头粉添加量为0%~20%时,鱼糜的蒸煮得率、保水性显著提高;当芋头粉添加量为20%~25%时,保水性无显著性变化。芋头粉添加量对巴沙鱼鱼糜的色泽影响显著,随着芋头粉添加量的增加,巴沙鱼鱼糜的亮度和白度下降,色泽偏黄绿色;随着芋头粉添加量的增加,巴沙鱼鱼糜的凝胶强度先升高后降低,当芋头粉添加量为20%时,凝胶强度达到最大值。与空白组对比,随着芋头粉添加量的增加,凝胶肌原纤维蛋白中α-螺旋上升,β-折叠下降,说明芋头粉能降低肌原纤维蛋白中α-螺旋转变为β-折叠的程度,使其形成致密的凝胶网络结构,凝胶也更具保水性。当芋头粉添加量为20%时,鱼糜的储能模量G′达到最大值,说明鱼糜在加热形成凝胶的过程中,弹性特征更明显。芋头粉膨胀后加固了蛋白的网络结构,增强了其凝胶特性,但是芋头粉添加量为25%时,鱼糜的凝胶网络结构遭到破坏,出现空洞结构。以上结果表明,当芋头粉添加量为15%~20%时可有效改善低盐巴沙鱼鱼糜的凝胶品质,并且制备的鱼糜富含膳食纤维。