山羊毛提取L-胱氨酸杂质源及其除杂工艺

山羊毛提取L 胱氨酸过程中伴有上百种有机类、无机类杂质的形成 ,分析杂质的形成过程及其对胱氨酸收率和产品质量的影响 ,采用料毛物理化学法除杂、活性炭两次脱色、三次中和重结晶除杂工艺 ,杂质除净率高 ,L 胱氨酸产品质量达HG 2 0 30 - 91优质品标准。     

重穗型杂交水稻籽粒灌浆过程中强势和弱势颖花内源IAA、ABA和GA水平的动态状况

研究了重穗型杂交水稻培矮 6 4s/E3 2的灌浆过程和强、弱势颖花中内源IAA、ABA和GA1 GA3水平的动态状况。籽粒发育过程中不同内源激素水平高低依次为 :IAA >GA1 GA3>ABA。IAA和ABA水平在强势颖花中较高而GA1 GA3水平在弱势颖花中较高。 3种激素水平的变化与谷粒增重速率之间均存在正相关 ,两个最高的相关系数值分别存在于单位鲜重样本的IAA含量(ng/gFW ) 与籽粒鲜重的增重速率之间 (r =0 .82 1 8 )和单个籽粒IAA含量 (ng/grain)与籽粒干重的增重速率之间 (r =0 .8485 )。推测启动和维持籽粒灌浆过程可能需要较高的IAA水平 ;ABA可能具有促进籽粒中同化物的累积和种子成熟的作用 ;GA1 GA3可能具有保持弱势颖花活性的特殊作用     

水稻单株有效穗数和每穗粒数的QTL剖析

应用292个Lemont/特青F13重组自交系（RILs)及其含272标记的遗传连锁图谱部析单株有效穗数（PN）和每穗粒数（SNP）及其相关性状的遗传,所有性状呈现超亲分离,PN与SNP存在弱的负相关,检测到影响PN和SNP及其相关性状的QTL51个和互作位点45对,它们可以解释60％以上的性状总变异,SNP与其相关性状的QTL定位在一起,比较与SNP－QTL同一或相邻区域的QTL数,穗部枝梗数是长度性状的两倍,故前者对SNP的作用更大,仅有2个PN－QTL与SNP相关性状的QTL相邻,因此通过标记辅助选择有可能实现PN与SNP的有利重组,其中影响PN的QPn4和影响穗枝梗数和长度的QPbn3a,QPbn3和QPb14等主效QTL,在标记辅助选择中具有重要的应用价值,对通过标记辅助选择合理配置穗部性状TQL产生新的高产穗型进行了讨论。     

蜘蛛神经节的解剖与神经细胞的分离培养

报道了虎纹捕鸟蛛(Ornithoctonus huwena)食道下神经节的解剖以及神经细胞的分离培养方法。为开展蜘蛛神经生物学实验方法的研究,创立了一种蜘蛛神经细胞解剖方法——去胸甲解剖法。神经节细胞培养基为NaCl2 23 mmol/L;KCl6.8 mmol/L;CaCl28 mmol/L;MgCl2 5.1 mmol/L;Sucrose 5 mmol/L;Hepes 10 mmol/L;谷氨酰胺1mmol/L;青霉素200IU/ml;链霉素200μg/ml;小牛血清20%;pH7.4。在温度(27±2)℃的培养箱中培养2~4h。实验结果表明与传统方法相比较,去胸甲解剖法具有取材简便、准确、快捷和高效的特点。改进的培养基非常适合蜘蛛离体神经细胞的培养。培养的细胞状态好、数量多,细胞体呈椭圆形,细胞形状近似汤勺,有一个长的单极突起,其大小为10~30μm。     

CO2浓度升高和不同氮肥水平下源库处理对粳稻茎鞘非结构性碳水化合物积累和转运的影响

为探究CO₂浓度升高和不同氮肥水平下源库处理对粳稻茎鞘非结构性碳水化合物(NSC)积累和转运的影响,利用开顶式气室(OTC),设置2个CO₂浓度([CO₂]):对照(背景大气,a[CO₂])和在背景大气[CO₂]基础上升高200μmol·mol^-1(e[CO₂])。以常规粳稻"南粳9108"为试验材料,在OTC内采用盆栽方式,设置低N(N1,10 g N·m^-2)、中N(N2,20 g N·m^-2)和高N(N3,30 g N·m^-2)3个施N水平。抽穗期源库改变设剪叶(LC)和疏花(SR)处理,以不处理为对照。测定并计算了抽穗期和成熟期叶片N含量、茎鞘NSC积累量(TM_NSC)、NSC表观转运量(ATMNSC)及其对籽粒产量的表观贡献率(AC_NSC)。采用方差分析、相关分析和逐步回归方法对上述观测数据进行分析。结果表明,[CO₂]升高显著降低抽穗期叶片N含量,显著促进中N水平的NSC积累。在不同[CO₂]和N水平下,SR处理均导致成熟期茎鞘TM_NSC显著升高,ATM_NSC和AC_NSC显著降低;在背景大气和不同N水平下,LC处理均显著降低成熟期TM_NSC,显著提高ATM_NSC,但[CO₂]升高下LC处理对成熟期TM_NSC和ATM_NSC均无显著影响。LC处理对籽粒产量及其构成未产生显著影响。粒叶比越高,成熟期TM_NSC和千粒重越低,ATM_NSC、AC_NSC、籽粒产量和收获指数越高。综合影响AC_NSC的因素为粒叶比、抽穗期和成熟期TM_NSC;综合影响籽粒产量的因素为粒叶比、成熟期叶片N含量和TM_NSC,这些综合影响均可用多元回归模型定量表述。     

四种不同穗型小麦的穗部性状分析

为了通过研究不同长相穗型小麦穗部特性,以达到提高产量和挖掘穗部潜力的目的。本文对长方型、棍棒型、椭圆型和纺锤型四种不同长相穗型小麦品种的穗部性状特性进行了分析。结果表明不同穗型小麦在小花数、穗粒数、粒重等方面均表现出先升后降的二次曲线趋势,但不同穗型小麦表现趋势不同,长方型和椭圆型小麦在穗粒数、穗重、各粒位粒重等方面均优于棍棒型和纺锤型小麦,棍棒型小麦由于其特殊的穗型结构,在小穗密度、粒重等方面表现独特,纺锤型小麦在各方面表现均较差。结果表明,在小麦生产用种和品种选育上,穗型的选择至关重要。长方型小麦有提高小麦产量的潜力。     

Deterioration of ovary plays a key role in heat stress-induced spikelet sterility in sorghum

In sorghum (Sorghum bicolor [L.] Moench), the impact of heat stress during flowering on seed set is known, but mechanisms that lead to tolerance are not known. A diverse set of sorghum genotypes was tested under controlled environment and field conditions to ascertain the impact of heat stress on time-of-day of flowering, pollen viability, and ovarian tissue. A highly conserved early morning flowering was observed, wherein >90% of spikelets completed flowering within 30 min after dawn, both in inbreds and hybrids. A strong quantitative impact of heat stress was recorded before pollination (reduced pollen viability) and post pollination (reduced pollen tube growth and linear decline in fertility). Although viable pollen tube did reach the micropylar region, 100% spikelet sterility was recorded under 40/22°C (day/night temperatures), even in the tolerant genotype Macia. Heat stress induced significant damage to the ovarian tissue near the micropylar region, leading to highly condensed cytoplasmic contents and disintegrated nucleolus and nucleus in the susceptible genotype RTx430. Whereas, relatively less damages to ovarian cell organelles were observed in the tolerant genotype Macia under heat stress. Integrating higher tolerance in female reproductive organ will help in effective utilization of the early morning flowering mechanism to enhance sorghum productivity under current and future hotter climate.     

APETALA 2‐like genes AP2L2 and Q specify lemma identity and axillary floral meristem development in wheat

The spikelet is the basic unit of the grass inflorescence. In tetraploid (Triticum turgidum) and hexaploid wheat (Triticum aestivum), the spikelet is a short indeterminate branch with two proximal sterile bracts (glumes) followed by a variable number of florets, each including a bract (lemma) with an axillary flower. Varying levels of miR172 and/or its target gene Q (AP2L5) result in gradual transitions of glumes to lemmas, and vice versa. Here, we show that AP2L5 and its related paralog AP2L2 play critical and redundant roles in the specification of axillary floral meristems and lemma identity. AP2L2, also targeted by miR172, displayed similar expression profiles to AP2L5 during spikelet development. Loss‐of‐function mutants in both homeologs of AP2L2 (henceforth ap2l2) developed normal spikelets, but ap2l2 ap2l5 double mutants generated spikelets with multiple empty bracts before transitioning to florets. The coordinated nature of these changes suggest an early role of these genes in floret development. Moreover, the flowers of ap2l2 ap2l5 mutants showed organ defects in paleas and lodicules, including the homeotic conversion of lodicules into carpels. Mutations in the miR172 target site of AP2L2 were associated with reduced plant height, more compact spikes, promotion of lemma‐like characters in glumes and smaller lodicules. Taken together, our results show that the balance in the expression of miR172 and AP2‐like genes is crucial for the correct development of spikelets and florets, and that this balance has been altered during the process of wheat and barley (Hordeum vulgare) domestication. The manipulation of this regulatory module provides an opportunity to modify spikelet architecture and improve grain yield.     

QTL mapping of grain weight in rice and the validation of the QTL qTGW3.2

A recombinant inbred line (RIL) population bred from a cross between a javanica type (cv. D50) and an indica type (cv. HB277) rice was used to map seven quantitative trait loci (QTLs) for thousand grain weight (TGW). The loci were distributed on chromosomes 2, 3, 5, 6, 8 and 10. The chromosome 3 QTL qTGW3.2 was stably expressed over two years, and contributed 9–10% of the phenotypic variance. A residual heterozygous line (RHL) was selected from the RIL population and its selfed progeny was used to fine map qTGW3.2. In this “F₂” population, the QTL explained about 23% of the variance, rising to nearly 33% in the subsequent “F_2:3” generation. The physical location of qTGW3.2 was confined to a ~ 556 kb region flanked by the microsatellite loci RM16162 and RM16194. The region also contains other factors influencing certain yield-related traits, although it is also possible that qTGW3.2 affects these in a pleiotropic fashion.