Wheat Seed Presoaking for Improved Germination

Seed presoaking improves wheat germination under marginal moisture conditions. The duration of seed presoaking was studied at The University of Arid Agriculture, Rawalpindi, using 10 wheat varieties. Seed presoaking beyond 12 h does not improve germination further, and beyond 21 h, germination rate is drastically reduced.     

微波干燥与常规干燥中木材内含水率动态分布

以黑胡桃木材为对象,采用X射线扫描含水率分布测试方法,分析、比较了微波干燥与常规热风干燥过程中木材内部含水率动态分布规律.结果表明:在微波干燥和常规热风干燥过程中,木材内层含水率均高于表层,存在着整体性的内高外低的含水率梯度场;在接个微波干燥过程中,木材内部虽然出现了部分内层含水率低于外层的情况,存在着含水率分布的局部不均匀,但并未出现与常规热风干燥相反的含水率梯度;在微波干燥中,木材内部各层与表层含水率的差值随着干燥时间的延长逐渐降低.随着干燥过程的进行,常规热风干燥中木材芯层与表层含水率差呈现出先增加后减小的变化趋势.     

Identification of S-haplotypes of European cultivars of sour cherry

The sour cherry is known to exhibit the phenomenon of gametophytic self-incompatibility which prevents self-fertilization. In sour cherry, besides self-incompatible cultivars, there often occur self-compatible cultivars. This is due to the occurrence of natural mutations of the S-RNase or SFB genes and, consequently, loss of functionality of S-alleles. Here we present the results of the identification of S-haplotypes of 21 cultivars of sour cherry from various regions of Europe. The analyses were performed using methods based on the amplification of intron I and intron II of the S-RNase gene and fragments specific to the individual alleles of the S-RNase or SFB genes. The tested cultivars were found to contain 15 S-haplotypes: S₁, S_1?, S₄, S₆, S_6m, S_6m2, S₉, S₁₂, S₁₃, S_13?, S₂₆, S₃₅, S_36a, S_36b, and S_36b2. The most frequently occurring S-haplotypes were S_13? (61.9%), S_36a (57.1%), and S₂₆ (47.6%). On the basis of the results, 17 of the 21 cultivars were deduced to be self-compatible. The results will be of use in the production of sour cherry fruit by facilitating the selection of suitable pollinating cultivars. The results are also expected to be useful in the breeding of new cultivars of sour cherry when selecting genotypes for crosses.     

Cloning and Functional Analysis of Lycopene ε-Cyclase （lbL C Ye） Gene from Sweetpotato, Ipomoea batatas （L.） Lam.

This paper reported firstly successful cloning of lycopene ε-cyclase(IbLCYe) gene from sweetpotato,Ipomoea batatas(L.) Lam.Using rapid amplification of cDNA ends(RACE),IbLCYe gene was cloned from sweetpotato cv.Nongdafu 14 with high carotenoid content.The 1 805 bp cDNA sequence of IbLCYe gene contained a 1 236 bp open reading frame(ORF) encoding a 411 amino acids polypeptide with a molecular weight of 47 kDa and an isoelectric point(pI) of 6.95.IbLCYe protein contained one potential lycopene ε-cyclase domain and one potential FAD(flavinadenine dinucleotide)/NAD(P)(nicotinamide adenine dinucleotide phosphate)-binding domain,indicating that this protein shares the typical characteristics of LCYe proteins.The gDNA of IbLCYe gene was 4 029 bp and deduced to contain 5 introns and 6 exons.Real-time quantitative PCR analysis revealed that the expression level of IbLCYe gene was significantly higher in the storage roots of Nongdafu 14 than those in the leaves and stems.Transgenic tobacco(cv.Wisconsin 38) expressing IbLCYe gene accumulated significantly more β-carotene compared to the untransformed control plants.These results showed that IbLCYe gene has an important function for the accumulation of carotenoids of sweetpotato.     

甘蓝型油菜耐低温生长生理生化响应机制

为提高甘蓝型油菜耐寒育种过程中的筛选效率,研究甘蓝型油菜耐低温机理,以8个不同抗寒性的甘蓝型油菜为材料,对低温条件下各材料的生物量、叶绿素、脯氨酸和相对电导率进行测定,发现在室外平均气温2.75℃时,抗性材料的生物量、叶绿素和脯氨酸的累积量都显著高于敏感材料,相对电导率没有显著差异;当平均气温7.52℃回升至12.39℃,抗性材料和敏感材料生物量的累积量无显著差异;在恒定低温10℃/4℃处理下抗性材料和敏感材料在处理前3周生物量均持续累积,但从第4周开始敏感材料新叶出现白斑,生物量减少,抗性材料老叶出现白斑,生物量维持不变。结果表明,耐低温材料在低温条件下叶绿素含量受到的影响较小,脯氨酸的积累量持续上升,具有较强的快速适应能力,在低温下具有显著的持续生长优势。     

Effect of nitrogen fertilization on nitrogen dynamics in oilseed rape using 15N‐labeling field experiment

In order to optimize nitrogen (N) fertilization and to reduce the environmental impact of oilseed rape without decreasing yield, a clearer understanding of N dynamics inside the plant is crucial. The present investigation therefore aimed to study the effects of different N‐application rates on the dynamics of N uptake, partitioning, and remobilization. The experiment was conducted on winter oilseed rape (Brassica napus L. cv. Capitol) under three levels of N input (0, 100, and 200 kg N ha^–1) from stem elongation to maturity using ¹⁵N‐labeling technique to distinguish between N uptake and N retranslocation in the plant. Nitrogen fertilization affected the time‐course of N uptake and also the allocation of N taken up from flowering to maturity. Most pod N came from N remobilization, and leaves accounted for the largest source of remobilized N regardless the N‐application rate. However, the contribution of leaves to the remobilized N pool increased with the N dose whereas the one of taproot decreased. Stems were the main sink for remobilized N from stem elongation to flowering. Leaves remained longer on N200 than on N0 and N100 plants, and N concentration in fallen leaves increased with the N treatment and in N100 plants along an axial gradient from the basal to the upper leaves. Overall, these results show that the timing of N supply is more crucial than the N amount to attain a high N efficiency.     

Combining Ability Analyses of Net Photosynthesis annuum Rate in Pepper （Capsicum annuum L.）

In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by （1/2） n （n- 1） diallel crosses. There are relatively large differences not only in general combining ability （GCA） effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability （SCA） effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties.     

盐胁迫对凤仙花种子萌发的影响

采用浓度为0%、0.2%、0.4%、0.6%、0.8%、1.0%的NaCl、Na2CO3、NaHCO3单盐胁迫凤仙花种子,通过对种子萌发特性的观察,研究不同盐分对其危害程度。结果表明:3种盐胁迫对凤仙花种子的萌发时滞、发芽率、发芽势、生长速度的影响差异明显。相同浓度下,Na2CO3胁迫时发芽率和生长速度受到显著抑制,NaCl胁迫时,发芽和生长受到的影响较小;NaHCO3胁迫时受到的抑制介于中间。综合分析,3种盐对凤仙花种子萌发影响的强弱顺序为:Na2CO3NaHCO3NaCl。     

不同盐碱区菊芋植株K~+和Na~+的分布特征

[目的]研究不同盐碱区域对菊芋离子分布的影响。[方法]以红块茎菊芋品种JY1及白块茎菊芋品种NY1、BY1为试验材料,研究了非盐、轻盐、重盐3种不同盐碱区条件下块茎、茎干和叶片的离子分布特征。[结果]随着土壤盐分的增加,菊芋茎干和叶片的K~+含量均增加,其中茎干中K~+含量显著增加,重盐下达到16.1 mg/g,达叶片的7.0倍以上;块茎K~+含量的变动幅度不大。随土壤盐分的增加,茎干、叶片、块茎的Na~+含量逐渐升高,其中茎干的增加幅度最大,重盐条件下Na~+含量较非盐条件下增加11.0倍以上;叶片Na~+含量的变化幅度不显著;重盐条件下,各部位Na~+含量从高到低依次为:茎干、块茎、叶片。植株各部位的K~+/Na~+从高到低依次为叶片、块茎、茎干。[结论]该研究可为耐盐品种的筛选及不同盐碱地条件下的菊芋栽培提供理论基础。     

华杂6号叶面积简易测定方法

研究了在直播条件下，华杂6号的叶长、叶宽、长宽乘积与叶面积，单叶面积与整株叶面积的关系。结果表明，华杂6号的单片叶面积与叶长、叶宽、长宽乘积都呈幂函数关系，但单片叶面积与长宽乘积关系最密切，其次是叶宽，最后是叶长。单株叶面积与单片叶面积呈一元线性函数关系，但相关性最好的叶片所处叶位，随绿叶数的增加而降低。