Small and round seed 5 gene encodes alpha-tubulin regulating seed cell elongation in rice

Seed size is an important trait in determinant of rice seed quality and yield. In this study, we report a novel semi-dominant mutant Small and round seed 5 (Srs5) that encodes alpha-tubulin protein. Lemma cell length was reduced in Srs5 compared with that of the wild-type. Mutants defective in the G-protein alpha subunit (d1-1) and brassinosteroid receptor, BRI1 (d61-2) also exhibited short seed phenotypes, the former due to impaired cell numbers and the latter due to impaired cell length. Seeds of the double mutant of Srs5 and d61-2 were smaller than those of Srs5 or d61-2. Furthermore, SRS5 and BRI1 genes were highly expressed in Srs5 and d61-2 mutants. These data indicate that SRS5 independently regulates cell elongation of the brassinosteroid signal transduction pathway     

Identification of a candidate elongation related gene in rice induced by GA

We identified a gibberellin-induced gene frag- ment in rice elongation by using differentialdisplay(DD)of mRNA.The rice seedlingscarried the eui(elongated)gene,named Zhen- chang A,were used,which were sensitive toGA_3 and elongated rapidly after application ofGA_3. The total RNA were extracted fromseedlings treated for 0,3,8,16,and 24 hwith GA_3(20mg/L),and the RNA of 8 hwere used to conduct mRNA DD assay.A to-tal of 44 DD cDNA fragments were obtained,which were induced or inhibited by GAs from100 combinations of anchor and arbitraryprimers in DD-PCR display(Fig 1).Of the 44DD fragments,GA15b cDNA fragment in- duced by GA_3 was cloned and sequenced.Thisfragment was 673bp in length and was accept-ed by GenBank with the accession number ofAF038894.GA15b gene encodes homology ofextension-like protein,a class of structural by-droxyproline rich glycoprotein of the plant ex-     

丸化剂对水稻种子出苗和秧苗生长的影响

以早稻品种金优974、湘早籼31号和晚稻品种新香优80、湘早籼10号为材料,比较研究了自研的丸化剂与进口种衣剂对水稻萌发、出苗、秧苗素质、苗期抗病虫能力的效应.结果表明,用丸化种衣剂包衣有利于种子发芽和出苗,提高秧苗综合素质.其中,成秧率提高6.8%～9.4%,秧苗根系活力提高7.1%～32.4%,病虫害防治效果分别达到95.7%～98.5%和77.5%～90.35%.     

水稻种质资源创新应用与思考

通过发掘和分析基因的结构和功能,对水稻种质进行分子遗传研究,并通过中间材料杂交,聚合多种有利性状,培育超级水稻种。     

Low temperature increased the biosynthesis of 2-AP,cooked rice elongation percentage and amylose content percentage in rice

Rice fragrance, cooked rice elongation and amylose content are some of the traits used in determining rice grain quality. 2-acetyl-1-pyrroline (2-AP) is the major compound that is responsible for fragrance in rice.This experiment was conducted with two indica rice cultivars: Meixiangzhan 2 and Xiangyaxiangzhan. Three temperature-controlled chambers: High (32 °C from 06:00 to 17:59 and 26 °C from 18:00 to 05:59), medium (27 °C from 06:00 to 17:59 and 21 °C from 18:00 to 05:59) and low (22 °C from 06:00 to 17:59 and 16 °C from 18:00 to 05:59) were used for the study. At the onset of heading, both cultivars were transferred to the three temperature-controlled chambers. Our results showed that in both cultivars, low temperature growth had the highest 2-AP content, while high temperature growth recorded the lowest 2-AP content. Principal component analysis showed remarkable differences in the metabolomes of rice grown in high, medium and low regimes. In the grains of both cultivars, we observed significant reduction in 2-AP content after 6 and 9 months of storage, however; 2-AP retention differed greatly in both cultivars. We also reported that low temperature growth increased cooked rice elongation percentage and the biosynthesis of amylose in rice. In conclusion, our findings will provide more information to breeders working on the improvement of rice grain quality.     

一项杂交稻制种花期调节新技术研究初报

杂交水稻制种的花遇优度 ,是种子生产的关键技术。近年来新老组合更替速度加快 ,且同一组合在不同地区、不同栽培技术体系下 ,其花期相遇时期也不尽相同 ,给种子生产带来一定的困难。花期调节一般在幼穗分化的早期即前三期 ,花期相差１～５天 ,可通过施肥、灌溉、喷施“九二○”及调节碳氮比等措施调节 ,效果明显。幼穗分化到了中后期 ,有的组合花期仍有偏差 ,常规的调节措施效果就显得不太明显。研究者从田间喷施除草剂对杂草的影响中得到启示 ,于２００１年夏正季在中国水稻研究所对农达除草剂调节水稻的生育期进行了尝试性研究 ,现将试验…     

Basal internode elongation of rice as affected by light intensity and leaf area

Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.     

Simulating seed reserve mobilization and seedling growth of rice in DSRICE1

The simulation of seed reserve mobilization and seedling growth of rice in the model DSRICE1 was analyzed using published data. Early plant DM patterns are characterized by a decline in total (kernel+seedling) DM during heterotrophy, and then an increase into exponential growth after CO₂ assimilation (autotrophy) begins. Data for a tropical japonica variety were used for qualitative comparisons of observed and predicted kernel and total DM. The published version of DSRICE1 was sequentially modified to (1) subtract respiration costs from mobilized reserves, (2) use a constant mobilization rate, (3) use the same partitioning fractions (PF) for both reserves and assimilates, and (4) assess the effects of leaching losses. After the first modification, the model reproduced observed DM patterns, and setting a constant mobilization rate allowed complete use of reserves. Using consistent PF values for both assimilates and reserves was justified because it simplified the model and had only slight effects on predictions. Predicted mobilization efficiencies (ME; g seedling g⁻¹ seed) were greater than measured values, but were improved by accounting for leaching losses. In sensitivity analyses, six seed-related parameters had significant effects on seedling DM at 14 days after seeding (DAS), but none significantly affected mature DM or yields. In other tests, the effects of four traits on seedling growth were assessed over their likely empirical ranges. The start of CO₂ assimilation (DAS) had the greatest effect, followed by the start of mobilization and seed mass. Mobilization rate had the smallest effect over its likely range. Finally, simulated and measured early PF values were significantly different, particularly for root partitioning. Predicted DM to 18 DAS using three sets of PF values also differed, although more for total DM per plant than for some plant parts. Using the measured PF values will likely improve the model. It was also demonstrated that simulating reserve mobilization allows dynamic responses to variation in environmental and cultural inputs that may have critical effects on later growth. Thus, the calibration of parameters such as initial DM and leaf area required in other models may be avoided. Most important, using a more process-based approach in DSRICE1 facilitates (or forces) realistic linkages between seedling growth and environment by management interactions, which can improve analyses of crop and weed establishment and management strategies.     

早稻种衣剂筛选试验初探

用6种种衣剂对早季水稻种子进行包衣。经筛选对比试验,结果表明：参试种衣剂对早稻种子发芽率无不良影响。能不同程度提高成秧率及秧苗素质,大部：分种衣剂处理能提高早稻产量。其中。友缘护苗、优富8号处理的单产比对照增产达极显著水平。浙江生物型2SB处理的单产比对照．增产达显著水平,友缘护苗、优富8号、浙江生物型ZSB三种种衣剂可在建瓯市作为早稻种子包衣剂进一步示范推广。     

15%多福水在水稻生产上应用效果

15％多福水稻种衣剂是安徽省六安地区种子公司安丰种衣剂厂生产的种子包衣剂,能有效杀灭种子携带的多种病原,具有促生长,提高成秧率、促根增蘖、增强抗冻、抗旱能力和增加产量的作用。 我县一直以来用常规药剂(强氯精)进行稻种的浸种消毒,此法虽可以杀死种子上携带的各种病菌,但农户操作繁琐,常因操作过程中技术掌握不好而影响杀菌效果,或引起药害,影响种子的发芽率,因此进行了15％多福水稻种衣剂对种子包衣杀菌效应和增产效果的试验和推广,现介绍如下： 一、试验材料和方法 供试水稻品种为早稻杂优组合金优402,试验于1999年3月20日在奉新县宋卜镇柘下村进行,试验田肥力中等。供试药剂为安徽省六安市种子公司安丰种衣剂厂生产的15％多福种衣剂和桂林强氯精厂生产的优质强氯精。     

对常规水稻种子繁育及销售工作的几点建议

水稻良种繁育单位要严格按种子繁育规程繁育良种;严格除杂除劣,保证种子纯度;安排好水稻新品种展示田;找好代销商;搞好稻农技术培训工作;适时召开水稻新品种观摩会;借助新闻媒体大力宣传。     

提高水稻成穗率的化学调控技术研究

提高水稻分蘖成穗率有两条化学调控途径,一是促进秧田分蘖和本田早发,二是控制水稻无效分蘖。研究表明,于秧苗1叶1心期喷施多效唑或应用烯效唑浸种,既可培育分蘖矮壮秧,又可起到促进本田早发的双重性生物学效应。在水稻盛蘖期喷施10~30mg/L浓度的赤霉素(“九二○”),可以控制无效分蘖,促进主茎和大分蘖的发育,提高分蘖成穗率14.80~21.80个百分点,增产效果达10%以上。于水稻够苗期喷施20mg/L浓度的“九二○”,再在拔节期配合喷施300mg/L浓度的多效唑,其增产幅度达18.1%。     

水稻种子田选留种子技术要点

针对苗种、贮藏种子不得当等问题,从霜前收割、防止混杂、种子的保管与贮藏等方面提出相应的解决办法,为水稻种子田选留种子提出相应对策。     

Physicochemical properties and in vitro digestion of extruded rice with grape seed proanthocyanidins

To characterize the impact of grape seed proanthocyanidins (GSPAs) on the physicochemical properties and in vitro digestibility of extruded rice, the XRD, RVA, DSC, FT-IR, micro-CT, as well as the in vitro digestion model was applied. Compared with normal rice, the extruded rice with different proportions of GSPAs (0–1.5%) increased the color depth, enhanced the porosity, and changed the semi-crystalline structure of extruded rice from an A-type to a mixture of A- and V-types. The viscosity and thermal properties of extruded rice with GSPAs were also changed noticeably. Additionally, a significantly lower equilibrium hydrolysis and k constant were observed in extruded rice with GSPAs (p < 0.05). Those results indicated that extruded rice with GSPAs could be an attractive approach to produce rice starchy food with low digestibility.