Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

Utilizing the heterosis of indica/japonica hybrid rice (IJHR) is an effective way to further increase rice grain yield.Rational application of nitrogen (N) fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield potential.However,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain elusive.The purpose of this study was to clarify these issues.Three rice cultivars currently used...     

Comparative studies on some yield contributing traits of wheat sown in binary mixtures

Cultivar mixtures have been suggested as ways to increase crop productivity. This field study was conducted to investigate the competition among five cultivated varieties of wheat (Triticum aestivum L.) for the traits like plant height, flag leaf area, fertile tillers per plant, spike length, spikelets per spike, spike density, grain weight per spike, and seed index in relation to competition with yield per plant. It was observed that cultivar mixtures ought to be more productive than corresponding pure stands. Four binary combinations of Seher2006-Kohistan97, Farid2006-SH2002, SH2002-Shahkar95, and SH2002-Kohistan97 were superior in performance, showing land equivalent ratio (LER) values greater than one for plant height, fertile tillers per plant, spike density, grain weight per spike, and grain yield per plant. It was observed that the performance of binary mixtures was mainly due to the increased average performance in spike density, grain weight per spike, and grain yield per plant. The competitive ability of wheat varieties in mixtures was independent of each other for the respective traits, which lead to cumulative effects for the increased performance within the associates in mixtures.     

Higher leaf area through leaf width and lower leaf angle were the primary morphological traits for yield advantage of japonica/indica hybrids

The yield potential of japonica/indica hybrids (JIH) has been achieved over 13.5 t ha⁻¹ in large-scale rice fields, and some physiological traits for yield advantage of JIH over japonica inbred rice (JI) and indica hybrid rice (IH) were also identified. To date, little attention has been paid to morphological traits for yield advantage of JIH over JI and IH. For this reason, three JIH, three JI, and three IH were field-grown at East China (Ningbo, Zhejiang Province) in 2015 and 2016. Compared with JI and IH, JIH had 14.3 and 20.8% higher grain yield, respectively, attributed to its more spikelets per panicle and relatively high percentage of filled grains. The advantage in spikelets per panicle of JIH over JI and IH was shown in number of grains on the upper, middle, and lower branches. Compared with JI and IH, JIH had higher leaf area through leaf width and lower leaf angle of upper three leaves, higher leaf area index and leaf area per tiller at heading and maturity stages, higher stem weight per tiller and K and Si concentrations of stem at maturity, higher dry matter weight in leaf, stem, and panicle at heading and maturity stages, and higher biomass accumulation after heading and lower biomass translocation from stem during ripening. Leaf width of upper three leaves were correlated positively, while leaf angle of upper three leaves were correlated negatively with biomass accumulation after heading, stem weight per tiller, and per unit length. Our results indicated that the grain yield advantage of JIH was ascribed mainly to the more spikelets per panicle and relatively high percentage of filled grains. Higher leaf area through leaf width and more erect leaves were associated with improved biomass accumulation and stem weighing during ripening, and were the primary morphological traits underlying higher grain yield of JIH.     

Growth characteristics and grain yield of machine-transplanted medium indica hybrid rice with high daily yield

High-yield rice varieties with a suitable growth duration are required for mechanical transplanting in multiple cropping systems. Daily yield is an appropriate criterion for the selection of machine-transplanted rice varieties. The aim of this study was to investigate the growth characteristics and grain production in machine-transplanted medium indica hybrid rice with a high daily yield. We conducted a field experiment on 20 medium indica hybrid rice varieties in 2017 and 2018.Grain yield decre...     

高粱杂交种茎叶产量与能源品质性状相关性分析

为分析能源高粱杂交种茎叶产量与品质性状之间相关关系,以96份能源高粱杂交种为材料,采用完全随机区组设计,在华北平原自然环境差异较大的2个试点地区栽培,测定茎和叶产量及7个茎叶中与能源相关成分含量.结果 表明,能源高粱杂交种能源相关性状变异系数在山西省介休市和河北省涿州市分别为3.7％～61.3％和4.8％～60.0％....     

Yield characteristics of japonica/indica hybrids rice in the middle and lower reaches of the Yangtze River in China

Although a lot of researches have been done on yield characteristics of japonica/indica hybrid rice, there is little information on differences of yield characteristics between different types of hybrid. To determine common characteristics of japonica/indica hybrid rice(JIHR) and identify the differences between different types of JIHR, the present study assessed yield characteristics, such as panicle trait, leaf area index(LAI), above-ground biomass accumulation, and nitrogen absorption and utilization, among three types of cultivar of JIHR. In our field experiments, three types of JIHR, e.g., Yongyou, Chunyou and Jiayouzhongke, were divided, and each of them has two cultivars, which were used as materials, meanwhile, using conventional japonica rice(CJR) Wuyingjing 31 and Sujing 9 were as controls. The results showed that the mean yield of those JIHR was above 12 t ha–1 in 2017 and 2018, and was 31.9 and 32.2%, respectively higher than that of CJR in the two years. Spikelet number per panicle of JIHR resulted in high yield. Higher yield of JIHR was likely contributed to greater panicle number and more spikelets per panicle. Higher yielding JIHR showed stronger tillering capacity, larger LAI and above-ground biomass accumulation from jointing to heading stages, which likely contributed to the higher number of spikelets per panicle. The long duration from heading to maturity stages allowed more nitrogen accumulation of higher yielding JIHR.     

高产粳稻沈农265产量相关性状的QTL分析

利用沈农265/丽江新团黑谷的176个F2 3家系群体构建包含90个SSR标记的连锁图谱,并对穗长、每穗颖花数、每穗实粒数、着粒密度、结实率、有效穗数和千粒重等7个产量相关性状进行QTL分析。结果表明,共检测到15个控制产量性状的QTL,分布在第3、4、6、8、9以及第12染色体上。包括3个控制穗长的QTL;3个控制每穗颖花数的QTL;1个控制每穗实粒数的QTL;2个控制着粒密度的QTL;2个控制结实率的QTL;3个控制千粒重的QTL以及1个控制有效穗数的QTL。其中,主效QTL有4个,分别是qPL9,qSPP4-1,qSD9和qRG12。这些QTL将为水稻分子设计育种提供"元件",同时为阐明水稻产量相关性状分子机制提供基础信息。     

灌水对河西绿洲冬小麦产量及光合生理指标的影响

在河西绿洲生态条件下,研究了不同灌水处理对冬小麦产量及相关指标的影响.在冬水灌量相等的基础上分别在拔节期(J)、抽穗期(H)和灌浆期(F)设等量不等次、等次不等量共5种灌水处理,灌水量分别为J1650m3/hm2(W1)J、1200 m3/hm2+H1050 m3/hm2(W2)J、1050 m3/hm2+H1050 m3/hm2+F1050 m3/hm2(W3)、J750m3/hm2+H750 m3/hm2+F750 m3/hm2(W4)J、1050 m3/hm2+H750 m3/hm2+F450 m3/hm2(W5).结果表明:各处理间单位面积籽粒产量、穗粒数、千粒质量、水分利用效率(WUE)、叶面积指数(LAI)、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和叶片相对含水量(RWC)均存在着显著或极显著的差异.籽粒产量以灌水量最多的W3处理最高,适量减少灌水量可以提高WUE.不同灌水处理下影响产量的主要因素是千粒质量和穗粒数.产量与开花期Pn呈显著正相关,但与各测定时期的Pn均值呈显著负相关.株高、生物产量、千粒质量、穗粒数等农艺指标与Pn呈阶段性相关.Pn、Tr、Gs和叶片RWC的相关性随生育时期的不同而变化.     

Dry matter production and panicle characteristics of high yield and good taste indica hybrid rice varieties

Indica hybrid rice (Oryza sativa) production aims to achieve two crucial targets: high yield and good taste. This study selected three types of indica hybrid rice according to grain yield and taste value, including high yield and good taste (HYGT), low yield and good taste (LYGT), and high yield and poor taste (HYPT), to analyze yield components, corresponding growth characteristics, and rice taste quality. When values were averaged across varieties and years, there were almost no differences in taste value between HYGT and LYGT; HYGT showed a significant increase in yield, owing to a higher number of panicles and spikelets per panicle, with a respective increment of 16.2 and 20.6%. The higher grain yield of HYGT compared with LYGT was attributed to three key factors: a higher leaf area index (LAI) during heading, a higher ratio of grain to leaf, and a higher biomass accumulation at maturity. HYGT and HYPT achieved similar high yields; however, HYGT had more panicle numbers and lower grain weight. In addition, HYGT showed a significantly higher taste value than HYPT, attributed to its significantly lower protein and amylose contents, with reductions of 8.8 and 15.7%, respectively. Lower protein and amylose contents might be caused by a proper matter translocation from vegetative organs to panicle. This study suggested that reasonable panicle characteristics and translocation efficiency from vegetative organs to panicle during heading to maturity are the key factors in balancing yield and rice taste quality. These results will provide valuable insights for rice breeders to improve the grain yield and quality of indica hybrid rice.     

不同氮肥运筹下玉米根系特征与产量的关系

明确玉米(Zea mays L.)根系性状对氮肥的响应特征及其与产量的关系,是揭示玉米氮营养机制、优化氮肥管理策略的基础。以供试玉米品种‘安农591’为试材,于2022年设置6种氮肥处理,即：不施氮(CK)、氮肥全部基施(N10)、基肥70%+拔节肥30% (N7∶3)、基肥50%+拔节肥50% (N5∶5)、基肥30%+拔节肥50%+大喇叭口肥20% (N3∶5∶2)、基肥20%+拔节肥40%+大喇叭口肥40% (N2:4:4),研究不同氮肥运筹下玉米根系性状的变化特征,并分析根系性状与产量的关系。结果表明,与CK相比,施氮提高吐丝期玉米根总长度、根表面积、根平均直径、根尖数、根体积、根组织质量密度和根系活力,降低比根长、根比表面积和根冠比。N7:3和N5:5处理的籽粒产量和全株生物量较高,其籽粒产量比N10处理提高6.6% ~ 7.3%。施氮降低成熟期玉米根干物质分配比例,提高籽粒干物质分配比例。适当氮肥后移有提高氮肥农学效率的趋势。玉米产量与吐丝期比根长和根冠比呈负相关,与根总长度、根表面积、根尖数、根系体积和根系活力呈正相关(P < 0.05)。在10种根系性状中,根总长度、根系活力、根表面积、根尖数和根冠比对产量影响较强,根平均直径、比根长、根表面积、根组织质量密度和根比表面积对氮肥农学效率影响较强。上述性状分别反映的是玉米产量潜力和氮肥利用率的重要根系性状。     

Continuous applications of biochar to rice: Effects on grain yield and yield attributes

Biochar is considered as a beneficial soil amendment for crop production. However, limited information is available on the effects of continuous applications of biochar on rice. In this study, a fixed field experiment was conducted in the early and late rice-growing seasons from 2015 to 2017. Grain yield and yield attributes with a widely-grown rice cultivar Zhongzao 39 were compared, with and without applications of biochar in each season. The results showed that grain yield initially decreased with biochar applications in the first three seasons due to decreases in grain weight and harvest index. Although there were further relative decreases in grain weight and harvest index for rice that was supplied with biochar in the fourth to sixth seasons, grain yield was increased(by 4–10%) because of increases in sink size(spikelets per m2) and total biomass. The increased sink size in rice whose soil had been supplied with biochar in the fourth to sixth seasons was achieved by increasing panicle size(spikelets per panicle) or number of panicles, or both. Our study suggests that the positive effects of biochar application on rice yield and yield attributes depend on the duration of biochar application. Further investigations are needed to determine what are the soil and physiological processes for producing yield responses associated with ongoing applications of biochar. Also, it should be evaluated the performance of biochar application combined with other management practices, especially those can increase the grain weight and harvest index in rice production.     

水稻物质生产特性及其与产量的关系研究

以汕优63、Ⅱ优162、Ⅱ优419、K18A/149和65002为材料,在云南省涛源乡、宾川县和杭州市富阳县进行试验,分析了水稻高产的物质生长特性,并比较了不同环境下物质生长特性的差异及原因。结果表明:云南涛源和宾川产量分别比杭州高80%和66%,导致云南产量较高的主要原因是生物产量较高。生物产量差异主要在幼穗分化以后,尤其是灌浆结实期。在云南生态条件下,中后期能容纳较高的叶面积系数(LAI),群体生长速率(CGR)较高,使花后物质生产量大,且花后物质运转量也较高。     

不同水稻群体产量性状、质量性状与产量的相关分析

选取30个不同熟期的水稻品种为试验材料,分别测定各品种的有效穗数、穗粒数、结实率、千粒重、叶面积指数、总干物质生产量、粒叶比、单茎茎鞘重和株高,采用相关分析方法,研究不同水稻群体产量构成性状、群体质量性状间及其与产量的关系。结果表明,针对不同水稻群体,其千粒重、穗数、每穗粒数、结实率与水稻产量的相关关系并不完全一致,以结实率表现最明显;水稻群体质量性状与产量的相关关系在不同群体中也表现不一致,以粒叶比与产量的相关关系变化最明显。因此,在生产实践中,针对不同群体,明确不同产量性状和群体质量性状在产量形成中的作用,应抓住重点性状并协调其与产量的相互影响和制约作用,以获得水稻最高产量。     

南方水稻机插现状与发展分析

\t\t\t\t\t目的\t\t\t\t\t探明机插杂交籼稻库源关系、干物质生产对氮素后移的响应及其与产量的关系。 \t\t\t\t \t\t\t\t \t\t\t\t\t方法\t\t\t\t\t以三系杂交水稻渝香203和渝优7109为材料,设置常规施氮处理N₁、不同氮素后移处理N₂、N₃、N₄和对照处理CK,比较叶面积指数(LAI)、粒叶比、干物质积累及其与产量的关系。\t\t\t\t\t \t\t\t\t \t\t\t\t \t\t\t\t\t结果\t\t\t\t\t较CK处理,施氮处理提高了有效穗数和穗粒数,产量增加。不同氮素处理产量高低顺序为N₄>N₃>N₁>N₂。较N₁处理,不同氮素后移降低了抽穗期LAI,渝优7109的N₄处理降幅达显著水平。较N₁处理,氮素后移处理(N₄)增加渝香203颖花叶比、实粒叶比和粒重叶比分别为10.2%、25.0%和29.3%,增加渝优7109分别为17.4%、18.5%和19.2%。较N₁处理,氮素后移处理(N₄)花前干物质积累量较低,而花后干物质积累和作物生长速率明显增加,群体花后光合优势明显,生物产量显著提高。\t\t\t\t\t \t\t\t\t \t\t\t\t \t\t\t\t\t结论\t\t\t\t\t氮素后移处理(N₄)通过适度减小机插杂交籼稻花前物质生产而增加花后作物生长速率和生物产量,提高粒叶比,在一定有效穗基础上增加了每穗粒数,从而增加了产量。\t\t\t\t\t\t\t\t\t     

Comparisons of yield performance and nitrogen response between hybrid and inbred rice under different ecological conditions in southern China

In order to understand the yield performance and nitrogen(N) response of hybrid rice under different ecological conditions in southern China, field experiments were conducted in Huaiji County of Guangdong Province, Binyang of Guangxi Zhuang Autonomous Region and Changsha City of Hunan Province, southern China in 2011 and 2012. Two hybrid(Liangyoupeijiu and Y-liangyou 1) and two inbred rice cultivars(Yuxiangyouzhan and Huanghuazhan) were grown under three N treatments(N1, 225 kg ha–1; N2, 112.5–176 kg ha–1; N3, 0 kg ha–1) in each location. Results showed that grain yield was higher in Changsha than in Huaiji and Binyang for both hybrid and inbred cultivars. The higher grain yield in Changsha was attributed to larger panicle size(spikelets per panicle) and higher biomass production. Consistently higher grain yield in hybrid than in inbred cultivars was observed in Changsha but not in Huaiji and Binyang. Higher grain weight and higher biomass production were responsible for the higher grain yield in hybrid than in inbred cultivars in Changsha. The better crop performance of rice(especially hybrid cultivars) in Changsha was associated with its temperature conditions and indigenous soil N. N2 had higher internal N use efficiency, recovery efficiency of applied N, agronomic N use efficiency, and partial factor productivity of applied N than N1 for both hybrid and inbred cultivars, while the difference in grain yield between N1 and N2 was relatively small. Our study suggests that whether hybrid rice can outyield inbred rice to some extent depends on the ecological conditions, and N use efficiency can be increased by using improved nitrogen management such as site-specific N management in both hybrid and inbred rice production.     

Effect of various combinations of temperature during different phenological periods on indica rice yield and quality in the Yangtze River Basin in China

Rice grain yield and quality declines are due to unsuitable temperatures from wide regions and various sowing dates.This study aimed to evaluate the effects of temperature on rice yield and quality at different phenological periods and obtain suitable temperatures for phenological periods in the Yangtze River Basin,China.This study conducted experiments on different sowing dates under different areas in the Yangtze River Basin to observe and compare the differences in rice growth,yield,and quali...     

杂交稻产量与主要农艺性状的灰色关联度分析

采用灰色关联度分析法分析了12个杂交稻品种（丰两优4号、杨农优3611、先农303、金优987、东优1388、丰优126、45S/RX10、荆楚优1537、II优838、香优218、川香29A／AW03和SD-88）产量与单位面积有效穗数、株高、穗长、每穗粒数、结实率和粒重的关系。结果表明：12个杂交稻品种产量与6个农艺性状关联度的降序排列为：单位面积有效穗数（0．742）、结实率（0．739）、穗长（0．705）、粒重（0．657）、每穗粒数（0．639）、株高（0．614）。由此可见,适宜的单位面积有效穗数、结实率和穗长可能成为今后杂交稻育种与栽培管理工作的主攻方向。     

早籼稻谷粒性状遗传效应的分析

以广陆矮４号等８个粗短粒品种和湘早籼３号等５个细长粒品种进行不完全双列杂交，采用加－显遗传模型，对早籼谷粒性状进行了遗传分析。结果表明，谷粒性状属于多基因控制的数量遗传。粒长、粒宽、粒厚、长宽比、粒重和穗重等性状主要受制于基因的加性效应，其狭义遗传率为５０．９％—９５．０％，均达极显著水平。相对遗传进度表明，长宽比性状的选择效果好于其它性状。亲本和杂交组合遗传效应预测值表明，在长粒品种中容易选出谷粒长宽比大和宽度小的亲本，而在谷粒厚度大的品种中则易选出粒重和穗重高的亲本。浙农９２１、湘８６－７０和湘早籼３号等亲本在粒形和产量性状改良中具有很大的增值作用，其中浙农９２１／湘８６－７０、中１５６／湘８６－７０和浙农９２１／湘早籼３号等组合能够显著降低粒宽、增加粒长和长宽比以及提高粒重和穗重。     

乙烯利不同施用方式对玉米农艺性状和产量的影响

采用乙烯利对玉米进行涂叶试验和顶冠层喷雾试验,以每个处理的节间长度相对于对照的降低百分率衡量各主要节间的短缩程度。结果表明,乙烯利对正在伸长的节间或其以上节间具有累加的抑制伸长效应和级联效应。在n片展开叶期对顶冠层喷药,伸长受抑制节间为从第n-2节开始的以上若干节间,尤以第n-1~n+4个节间伸长最易受到抑制,且通常以第n或第n-1个节间短缩程度最大;伴随节位的递升,大体上,自第n+4节以上的各个节间长度的降幅明显减小,但对雄穗节间例外。对于浚单20,叶龄指数为55到70之间是最佳施药期,可以显著提高抗倒伏能力;合理用量应以能够获得不低于对照95%的穗粒数和叶面积作为判断依据。     

两系杂交粳稻新品种“信杂粳1号”的栽培技术

介绍了易脱粒的两系杂交粳稻新品种信杂粳1号的主要特征特性和高产高效栽培技术。