水稻再生特性的生理基础研究Ⅰ.头季收获时叶绿体色素含量的影响

对头季收获时母体的叶绿体色素的含量与品种再生力的强弱进行了相关性研究。结果表明 :( 1 )头季收获时 ,主茎、分蘖茎、茎鞘各部分叶绿体色素含量与再生芽数不存在相关性 ,但三者之和与再生芽存在一定程度的相关性。 ( 2 )头季收获时母体各部位叶绿素a总量、叶绿素a +b总量与再生芽数达显著负相关 ,其中以叶绿素a总量与再生芽数的双曲线相关为最大 ,回归方程为Y再生芽 =-1 3 .63 86+1 8.83 3 2 /X叶绿素a总量(R =0 .82 0 1 )。

沼液配施化肥对盆栽樱桃萝卜生长及品质的影响

本试验研究沼液配施化肥对盆栽樱桃萝卜植株生长和品质的影响,以期为沼液合理利用和实现农作物优质高产提供理论参考。以荷兰引进的“爱斯特”樱桃萝卜为供试材料,采用施用方式和沼液配施化肥比例两因素进行试验,施用方式分为氮素基施和基施+追施两种,氮素基施分为只施用化肥(CF)和只施用沼液(CB)两种;氮素基施+追施分为在氮素总用量一定的前提下,不同比例沼液配施化肥,即沼液替代化肥氮素比例为25%(25BSF)、50%(50BSF)、75%(75BSF)和100%(100BSF),以不施肥(CK)为空白对照,研究沼液配施化肥及不同施用方式对樱桃萝卜发芽率、发芽势、叶片叶绿体色素含量、生长发育以及果实品质的影响。结果表明:(1)随着沼液施用量的增加,樱桃萝卜种子发芽率呈现出先升高后降低的趋势,发芽势呈逐渐下降趋势,75BSF处理的发芽率最高,较CK显著提高3.57%,较CF处理显著提高10.56%。(2)CB、25BSF、50BSF、75BSF和100BSF处理均能提高樱桃萝卜叶片的叶绿体色素含量、生长指标值以及可溶性糖和VC含量。随着沼液替代化肥氮素比例的增加,各指标值呈现出先升高后下降的趋势,其中,75BSF处理的叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量较CK分别显著提高54.84%、40.63%、50.96%和48.78%,较CF处理分别显著提高28.00%、25.00%、27.42%和29.79%;75BSF处理的樱桃萝卜获得最大的肉质根鲜重、干重及冠层鲜重、干重,分别比CK显著增加89.16%、88.89%、70.37%和34.29%,较CF处理分别显著提高13.72%、27.50%、33.72%和17.50%;75BSF处理有利于樱桃萝卜可溶性糖和VC的积累,较CK分别显著增加65.76%和78.53%,较CF处理分别显著增加35.22%和25.14%。总体来看,75BSF处理对樱桃萝卜的促生效果最好。综上所述,沼液配施化肥能有效改善樱桃萝卜植株的生长发育和叶绿体色素的合成,进而促进植株生物量和营养品质的提升,是一种减少化肥用量、消纳沼液、提高作物产量以及改善营养品质的施肥策略,因此生产中可以采用沼液替代化肥氮素75%的施用方式进行施肥。

小麦灌浆中后期喷施苯醚甲环唑对光合作用的影响研究

在小麦灌浆中后期喷施苯醚甲环唑,研究其对光合作用的影响。结果表明:叶绿体含量相对稳定期及光合速率高值持续期分别延长了2.6~2.9 d和3.2~3.4 d,对光合作用有着积极影响;可增产753.3~942.3 kg/hm^2,比对照增产8.79%~12.65%;增产主要贡献是千粒重,千粒重可增加4.1~5.2 g,比对照提高8.79%~12.53%。

GA_3对橡胶草生理特性及开花的影响

以橡胶草叶片为试材,喷施不同质量浓度[0 mg/L(CK)、50 mg/L(T1)、100 mg/L(T2)、150mg/L(T3)、200 mg/L(T4)、300 mg/L(T5)、600 mg/L(T6)]赤霉素(GA3),研究其对橡胶草叶片叶绿素含量、类胡萝卜素含量、酶活性、开花及主要开花性状的影响。结果表明:叶片喷施GA3后,随着时间的推移,各处理叶片叶绿素含量和类胡萝卜素含量整体上呈逐渐上升趋势,但上升幅度较小,且CK最高;GA3处理均使叶片SOD、POD、CAT活性下降,其中,T3的酶活性较其他处理低,T3叶片SOD活性在处理后10 d与CK相差最大,活性下降25.39%,活性最低峰时较CK下降11.81%;T3叶片CAT活性处理后10 d与CK相差最大,活性下降77.66%,活性最高峰时较CK下降44.00%;T3叶片POD活性在处理后20 d与CK相差最大,活性下降75.17%,处理后60 d与CK相差最小,POD活性下降32.13%。随着GA3质量浓度的增加,各处理营养生长期时间延长,开花推迟,花期缩短;花葶高度和花葶粗均呈现先升高后下降的趋势,开花数则呈下降趋势;而花直径差异不显著,但均与CK差异显著。综上,外施一定质量浓度的GA3对橡胶草花葶高、花葶粗、花直径生长均有一定的促进作用,且质量浓度为150 mg/L时促进效果最佳。

Effects of Shading on Photosynthetic Properties of Canopy and Single Leaf of Winter Wheat

[Objective] The aim was to study on the effects of long-term low radiation on canopy apparent photosynthetic rate （CAP） and photosynthetic properties of top three leaves of winter wheat, especially the flag leaf. [Method] Two winter wheat （Triticum aestivum L） cultivars, Yangmai 158 and Yangmai 11, which differed in low radiation resistance, were used to measure the CAP, photosynthetic rate （Pn） of the top three leaves, chlorophyll content of flag leaf and grain yield. In the test, three treatments were designed from jointing to maturity, as follows： control without shad- ing （So）, S1 and S2 treatments with 22% and 33% sunshine shaded. [Result] CAP of Yangmai 158 and Yangmai 11 declined with shading. Under low radiation, Pn of flag leaf declined significantly, while no obvious effects were found on Pn of the 2nd leaf, and Pn of the 3rn leaf increased significantly, which partially compensated the decrease of Pn of the flag leaf. In addition, the compensation effect differed in shading and cultivars： compensation effect in S1 group was higher than that of S2 and effect of Yangmai 158 was higher than that of Yangmai 11. During the period of high Pn. shading decreased the content of total chlorophyll, chlorophyll a, b, and a/b. [Conclusion] Under low radiation, the decrease of chlorophyll a and a/b led to substantial declining of Pn. and CAP declined accordingly, finally resulting in drop of grain yield. The research provides important theoretical basis for wheat production in the middle and lower reaches of Yangtze River.

盐胁迫对珠美海棠幼苗光合特性的影响

为研究盐胁迫对珠美海棠幼苗光合特性的影响,以珠美海棠(Malus zumi)盆栽幼苗为试验材料,测定它们在不同浓度NaCl胁迫下的光合参数和叶绿体色素含量及叶绿素荧光特性的变化。结果表明,盐胁迫下,珠美海棠幼苗的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、PSⅡ的潜在活性(Fv/F0)、PSⅡ实际光化学量子产量、叶绿素b都呈先上升后下降的趋势,胞间CO2浓度(Ci)呈先下降后上升的趋势,叶绿素a和类胡萝卜素均呈下降趋势。低盐浓度(50 mmol·L-1)下,光合相关参数值和叶绿素b含量均有所提高,说明珠美海棠幼苗对盐胁迫有一定适应能力;随着盐浓度升高,珠美海棠幼苗的光合参数、蒸腾速率、叶绿素含量有所降低,表明其光系统受到影响,进而使其光合性能降低。

Effects of Different Substrate Composition on Growth of Gesneriaceae Plants

The cultivation experiment was carried out to investigate the effects of dif-ferent proportions of peat soil, perlite, vermiculite and yel ow mud on growth of Gesneriaceae species （Chirita gueilinensis, Sinningia speciosa, Lysionotus pauci-florus, Hemiboea henryi, Aeschynanthus acuminatus, Saintpaulia ionantha）. The growth traits of each plant growing in 7 different matrix materials were investigated. The plant height, crown width and chlorophyl content of each plant were mea-sured. The results showed that the best substrate ratio was peat soil∶vermiculite=2∶1 for C. gueilinensis, L. pauciflorus and H. henryi; peat soil∶perlite∶vermiculite = 2∶1∶1 for S. ionantha; peat soil∶vermiculite∶yel ow mud=2∶1∶1 for S. speciosa; peat soil∶per-lite∶vermiculite∶yel ow mud=2∶1∶1∶1 for A. acuminatus.

Deletion of a Dna K protein gene causes seedling green-revertible albino by retarding chloroplast development in rice

Green-revertible albino mutants are important sources for studying chloroplast structure, chloroplast development, chlorophyll biosynthesis, and plant photo- synthesis. In the present study, we characterized a green- revertible albino mutant gra（k）, which was obtained from the tissue-cultured rice Kitaake. The mutant gra（k） exhib- ited albino on its first three leaves. The leaf color started to turn green at the four-leaf stage. The chlorophyll contents were deeply reduced at the seedling stage, and the chloroplast development was delayed in gra（k）. The green- revertible albino （gra） phenotype of the mutant gra（k） was temperature dependent. The main agronomic traits, including plant height, tilling number per plant, seed set- ting rate, and thousand-grain weight, slightly decreased in gra（k） comparing to those in the wild-type Kitaake. Genetic analysis showed that the gra phenotype was con- trolled by a single recessive nucleic gene. By using 5,168 recessive F2 individuals derived from the cross of gra（k） × Jodan, the locus of the gene Gra（k） was delimited in a DNA region of 200 kb between the makers B-31 and P11 on chromosome 5. Sequencing analysis indicated that the three functionally annotated genes, LOC_Os05g23700, LOC_Os05g23720, and LOC_Os05g23740, were all deleted in the 200 kb region in the mutant gra（k）. Trans- genic test revealed that the gra（k） plants over-expressing LOC_Os05g23740CDS were restored to normal green as the wild-type Kitaake. Our results proved that the deletion of the DnaK protein gene LOC_Os05g23740 （encoding the chaperon protein OsHsp70CP1） led to the gra phenotype in the mutant gra（k）.