Yield Of Different Cultivars Research Articles

Comparative Study of Ginger Cultivars under Shading Conditions in a High Tunnel

Ginger (Zingiber officinale Rosc.) is a valuable sciophyte crop used as a spice or fresh herb in culinary dishes and for treating medical issues such as osteoarthritis, neurological diseases, vomiting, and asthma. The demand for ginger in the United States is remarkably high; it is produced commercially and exclusively in Hawaii but can only meet ∼20% of US demand. Light for ginger growth may be more important than is often assumed, but the roles of light in ginger growth and rhizome yield are not fully understood. We hypothesized that artificial shade would produce the highest yielding ginger compared with no shade. This study evaluated the impact of different shading suited for ginger growth and rhizome yield of different cultivars grown in a high tunnel. There were three levels (0%, 22%, and 40%) of shade using RCBD design. We analyzed the overall yield (weight) of ginger and the specific yield (weight) of different rhizome parts (biological root, edible root, and seed ginger) per plant in addition to plant growth data. Data were analyzed for 2018 and 2019, and shade conditions influenced ginger growth and yield. There was no significant difference between shade conditions or cultivars, but general trends found that data differed between the two growing seasons. In 2018, Chinese White and Hawaii Yellow produced a better (higher) yield under 0% and 40% shade. However, in 2019, Chinese White and Hawaii Yellow produced the highest total yield under 22% shade, but Bubba Blue produced the highest overall yield at 0% shade.

Screening for Heat and Rain Tolerant Cultivars of Cauliflower for Cultivation in Monsoon Season in the Subtropical Region of Bhutan

There is a shortage of cauliflower in the domestic market during monsoon and early autumn seasons in Bhutan due to the absence of suitable cultivars for cultivation in subtropical region during these seasons. This study was conducted to assess the genotypic variability in yield of different cultivars of cauliflower under heat and rain (flood) stresses in the subtropical region. Four F1 hybrid varieties of cauliflower from the Takii Seeds, Japan (KSB-12.179, KSB-12.180, KSB-18.297 and KSB-20.320) and three F1 hybrid varieties from Syngenta Seeds, India (C-6099, CFL-1522 and Monsoon Queen) were evaluated in August 2022 in open field at ARDC Samtenling. The experiment was laid out in a RCDB design with three replications using Snow Mystique as the check variety. The objective of the study was to identify short duration, rain and heat tolerant varieties of cauliflower for cultivation in the monsoon season (July-August) in the subtropical region of Bhutan. In addition, all the cultivars were further assessed in September, and five cultivars that performed well in monsoon planting were evaluated in November 2022 as the second and third staggered planting trials to find out their performance in late monsoon and main seasons (September-November) respectively. The results from three staggered trials showed that Monsoon Queen matured in 53 days after transplanting (DAT), 56 DAT and 35 DAT in the first, second and third staggered planting trials with the mean head of 462 g, 376 g and 211 g respectively. In comparison, the check variety matured in 142 DAT, 114 DAT and 77 DAT in the first, second and third staggered planting trials with the mean head of 658 g, 403 g and 767 g, respectively. Monsoon Queen was the earliest maturing variety with good head weight and curd quality among the eight cauliflower varieties when transplanted in August 2022. However, both the head yield and curd quality of this cultivar declined in later plantings, indicating that this variety is not suitable for main season (autumn) planting. With the identification of Monsoon Queen as the heat and rain tolerant cultivar in this study, cauliflower can now be grown even in the monsoon season in the subtropical region of Bhutan.

Water Use Efficiency and Winter Wheat Grain Yield of Different Cultivars Under Different Irrigation Strategies in a Semi-arid Region

Water Use Efficiency and Winter Wheat Grain Yield of Different Cultivars Under Different Irrigation Strategies in a Semi-arid Region

Close relationship between potassium accumulation in internodes and translocation of non-structural carbohydrate to grains in rice cultivars with different yields

Potassium (K) is an important macronutrient together with nitrogen and phosphorous. Potassium mostly accumulates in the internodes of rice plants during ripening stage. Since internodes are responsible for translocation of carbohydrates to the grains during ripening, the involvement of internode K in grain yield has been suggested, however, the precise mechanism remains unclear. This study aims to examine the relationship between rice grain yield in different cultivars and the dynamics of K and non-structural carbohydrates (NSC) in the internodes during the ripening period. Field experiments were conducted to investigate the differences in the dynamics of K and NSCs in internodes from heading to maturation in 10 cultivars with different yields and three mutants with different grain numbers. To reveal the localization of K in internode tissues, we conducted laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis. During the early ripening period from heading to 14 days after heading (14 DAH), the decrease in NSC contents in lower internodes was higher in the high-yielding indica cultivars than in japonica cultivars. In the late ripening period from 14 DAH to maturing, re-accumulation of NSC in lower internodes was higher in the japonica than in the indica. In contrast, the increase in K contents in the internodes was larger in the indica than in the japonica throughout the ripening stage. In the internodes of low-yielding whole crop silage (WCS) cultivar, the NSC contents were maintained at high levels during ripening, while K contents were consistently low. Similar results were observed in the mutant with low grain numbers. The mutant had lower K contents and higher NSC contents than the wild type (WT). Correlation analysis of different cultivars indicated that the change in K content in whole internodes from heading to maturing was negatively correlated with the change in NSC content. LA-ICP-MS analysis of internode tissues of the indica cultivar revealed that K accumulated more in the parenchyma cells than in large vascular bundles. These results suggest that K accumulation in the internodes is positively correlated with NSC translocation from internodes to grains, which could be through indirect effect of K accumulation in parenchyma on enhancement of long distance transport of NSC from internodes to the grains. This study provides new insights into the mechanism underlying the role of K in grain filling, which would help improving usage of K fertilizer for optimum plant growth and yields.

Symbiotic interaction between a mixture of Bradyrhizobium japonicum strains and different soybean cultivars

Aim. To study the mutual relations between different soybean cultivars and two Bradyrhizobium japonicum strains after mixed inoculation, to evaluate the impact of the introduced microorganisms on the local rhizobial communities in soil, the formation and functioning symbiotic systems, and productivity of soybean. Methods. Microbiological and serological methods; field experiment, gas chromatography and mathematical-statistical methods. Results. A small- plot field experiment demonstrated that the use of a mixture of B. japonicum 46 and B. japonicum КВ11 strains pro- moted a more even distribution of the local and introduced rhizobia in the nodule populations of 12 soybean cultivars of different geographic origin. There was no domination of particular strains in the nodules, and the symbiotic systems formed were more balanced than the control without inoculation. After inoculation of the above-mentioned mixture, in most cultivars there was a considerable increase in the number of nodules (10–45 % more) and their mass (11–86 % increase). There was also an increase in the level of symbiotic nitrogen fixation with 1.2–4.2 times and an increase in the weight of grain per plant by 6–29 % (depending on the cultivar). The efficiency of a mixture of B. japonicum 46 and КВ11 strains in a preparation Rizogumin was confirmed in extensive field trials with soybean on an area of about 60 thousand ha in different regions of Ukraine. In the background of the local populations of the soybean nodulating bacteria in the areas, the application of the formulated mixture of the two rhizobia strains ensured a stable increase by 15–33 % in the soybean yield as compared with the control without the inoculation. Conclusions. A novel approach was investigated, which lies in the application of a mixture of B. japonicum 46 (genetic group USDA 6) and B. japoni- cum КВ11 (genetic group USDA 123) strains for different soybean cultivars inoculation. Combining these two strains and their introduction into agrocenoses ensured the formation of a balanced symbiotic systems (without clear domina- tion of some strains in the nodules). This was expressed in an intensified nodulation, symbiotic nitrogen fixation, and increased yield of different cultivars of soybeans by 15–33 % as compared to the control (without inoculation).

Elevated atmospheric CO2 and warming enhance the acquisition of soil-derived nitrogen rather than urea fertilizer by rice cultivars

Plant nitrogen (N) acquisition is essential to both crop growth and yield. A rational N management strategy for agricultural systems under climate change is required but a knowledge gap still exists regarding plant N uptake and N origin (soil-derived N or fertilizer-derived N) in response to elevated atmospheric CO2 and warming. Our study investigated the responses of soil- or fertilizer-derived N uptake and yield of different cultivars of rice (Oryza sativa L.) to climate change. Five cultivars in the pedigree of a widely-grown rice cultivar Wuyoudao1 were supplied with and without urea, a commonly used N fertilizer in paddy soils and grown in open-top chambers under elevated CO2 (700 ppm) and warming (2°C higher than the air temperature). Plant N origins were traced using 15N-labeling technique (urea of 5% 15N atom). Compared to the control, elevated CO2 and warming increased N uptake by 17%, irrespective of N supply. Soil-N rather than fertilizer-N was the source of the increased N uptake. The increased soil-N uptake resulted in the enhancement of rice yield under climate change. Urea application did not alter the yield response to elevated CO2 and warming compared to the non-N supply, but did stimulate plant uptake of the soil-derived N. Although genetic improvement of rice germplasm resulted in an increase in plant N acquisition and yield, the history of crop breeding since 1935 did not alter the climate-change-induced response in terms of plant N acquisition. Our results suggest that climate change may lead to the depletion of the recalcitrant soil N pool in paddy soils, and that fertilizer-N-use efficiency may need to be factored into future breeding for rice genotypes adapting well to climate change.

Effects of Weak- and Semi-Winter Cultivars of Wheat on Grain Yield and Agronomic Traits by Breaking through Traditional Area Planting

Global warming has changed the suitability of areas traditionally planted with crops, raising concerns about cereal security. To investigate the possibilities and constraints of increasing yields by breaking through traditional area plantings of wheat cultivars, a two-year field experiment was conducted in southern and northern locations in the Yangtze River basin (YRB), China (separated by approximately 180 km), with seven weak-winter types and six semi-winter types, respectively, bred for the two regions. The movement of weak-winter-type cultivars to the north increased or did not change grain yield and their grain yields were not significantly higher than those of local semi-winter-type cultivars. The movement of semi-winter-type cultivars to the south significantly decreased their yields. Thus, breaking through traditional area plantings did not significantly increase grain yields compared with those of local wheat cultivars. Grain yield of wheat planted in the northern YRB was higher by 5 to 20% than that in the southern YRB because of an increase in spikes that resulted from a longer spike formation phase. In addition, the post-anthesis leaf area declined more slowly in the northern YRB because of higher main stem and tiller survival. High-yielding cultivars always had more spikes and larger photosynthetic areas after anthesis than those of low-yielding cultivars regardless of the planting locations, which led to increases in post-anthesis biomass. However, the grain yield of different cultivars was highly variable under different environmental conditions. The coefficient of variation (CV) of grain yield in different cultivars was significantly positively correlated with the CV of spike number and post-anthesis biomass, implying that flexibility spike number and post-anthesis biomass in response to environmental changes can maximize release of yield potential. Therefore, improving main stem and tiller survival can increase spike number and maintain post-anthesis photosynthetic areas and help to establish a large, highly stable, and productive population with a high level of suitability and production through effectively utilizing the resources during the late growth phase. Valuable suggestions for breeding high-yield and -stability cultivars and confirming their planting range in the future are given.

Influence on Yield of Different Cultivars of Paddy under Various Cultivation Methods in Relation to Weather Parameters

An experiment entitled, “Studies on effect of different paddy cultivars with various cultivation methods of paddy in relation to weather parameters.” was carried out during kharif, 2018 at Agricultural Research Station Farm,Vadgaon Maval, Tal. Maval, Dist. Pune. The field experiment was laid out in split plot design with three replications. There were sixteen treatment combinations comprising of four varieties viz., VDN-3-51-18 (Indrayani), VDN-99-29 (PhuleSamruddhi), IET-13549 (Bhogawati) and RDN-99-1 (Phule Radha) and four cultivation methods viz., M1 : Four Point Agro Technique (Char Sutri Method), M2 : Drilling at 22.5 cm, M3: Saguna Rice Technique (SRT) and M4 : Modified Direct Seeded Rice Technique (MDSRT). The gross plot sizewas3.40 m x 3.40 m. From the data it was observed that sowing of paddy varieties with Modified Direct Seeded Rice Technique (MDSRT) favorably influenced all the yield components. This is due to positive correlation with minimum temperature, RH I and RH II. It would be, therefore, suggested to adopt sowing paddy variety Phule Samruddhi or Indrayani with Modified Direct Seeded Rice Technique (MDSRT) to obtain maximum yield.

Effect of Various Sowing Methods of Direct Seeded Rice on Yield of Different Cultivars in Relation to Weather Parameters

The field experiment on effect of weather parameters on different rice cultivars with various sowing methods of direct seeded rice was carried out during kharif, 2017 at Agricultural Research Station Farm, Vadgaon Maval, Tal. Maval, Dist. Pune. It was laid out in split plot design with three replications. There were sixteen treatment combinations comprising of four sowing methods and four varieties. Among the four different varieties of paddy, VDN-99-29 (Phule Samruddhi) recorded significantly higher increased yield when sown on raised bed (15-25 x 15-25 cm). It would be, therefore, suggested to adopt direct sowing of paddy variety Phule Samruddhi,on raised bed (15-25 x 15-25 cm) to obtain higher yield.

Leveraging of hyperspectral remote sensing on estimating biomass yield of Moringa oleifera Lam. medicinal plant

Moringa oleifera Lam. is a functional plant considered to be high in nutrients as well as medicinal properties, largely utilised in most of the developing countries. Therefore, early prediction of M. oleifera biomass yield is a valuable pre- and post-harvest planning strategy for ensuring a reliable supply of the plant products and for marketing purposes. Subsequently, the objective of the current study was to explore the potential use of hyperspectral data in predicting biomass yield of different cultivars of M. oleifera. Canopy hyperspectral data were collected on five M. oleifera cultivars when they were one month and two months old using a hand-held spectroradiometer. The M. oleifera plants were harvested after two months and their leaves as well as stems were separated and immediately (i.e. within a minute) weighed (g plant −1). First-order derivative was used to transform the reflectance spectra and analysis of variance (ANOVA) as well as random forest (RF) regression and classification algorithm were used to analyse the data. The results showed that the first-order spectra of the five cultivars were significantly different (p ≤ 0.05) from each other in most portions of the electromagnetic spectrum. Furthermore, the results indicated that the studied M. oleifera cultivars can be discriminated from each other using their first-order derivative of reflectance and RF classifier. RF regression models developed to predict the biomass yield of a two-month old M. oleifera crop were more accurate compared to the models developed when the plant was month old. The relative root mean square error of validation (RRMSEV) for biomass models of two-months old plants ranged between 23 and 37%, while the RRMSEV for biomass models of one-month-old plants ranged between 30 and 59%. Cultivar Tanzania obtained the most accurate whole plant biomass yield prediction model with a RRMSEV of 23.20%. When the data aggregated across the five cultivars to develop a universal model, the results showed R2 = 0.59: RMSEV = 6.47 g plant−1; RRMSEV =29.42% for the whole plant biomass yield, R2 = 0.52, RMSEV = 4.78 g plant−1RRMSEV =29.51% for the leaves biomass yield and R2 = 0.42; RMSEV = 2.17 g plant−1 RRMSEV = 37.35% for the stem biomass yield. Based on current results, the study infers that combined spectral data across different cultivars may not be useful in estimating M. oleifera biomass yield. The results underscore the use of hyperspectral data as a quick non-destructive means to measure the yield of M. oleifera medicinal plant. Furthermore, the present study gives an insight into the potential of hyperspectral data to be extrapolated to larger scales for prediction of biomass yield of medicinal plants using spaceborne and airborne acquired data.

Impact of plant growth substances on corm and cormel yield of different cultivars of gladiolus (Gladiolus grandiflorus L.)

Gladiolus is a flower of glamour and perfection which is known as the queen of bulbous flowers and grown as flower bed in garden. Plant growth substances promote more number of quality corm production in gladiolus. Hence, the present study was conducted to study the impact of plant growth substances in gladiolus at Research cum Instructional Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.). The five gladiolus cultivars i.e., Saffron, Summer shine yellow, American beauty, Candyman and White prosperity were tested with plant growth substances viz., GA3 @ 100 ppm + Vermicompost @ 80 g/ pot, CCC @ 500 ppm, Humic acid @ 0.1% + Chicken manure @ 10 g/pot, Salicylic acid @ 150 ppm and control (distilled water) in Factorial Completely Randomized Design with three replications during Rabi season 2016-17. The plant growth substances were sprayed with the help of a sprayer and the organic manures (Vermicompost, Chicken manure) was given by soil application at two, four, six leaves and flowering stage. It was observed that the experimental cultivars were exhibited genotypic variation regarding corm and cormel number, size, weight and diameters. The cultivar American beauty having maximum number of cormels whereas, cultivar White prosperity having significantly highest corm weight, corm diameter and cormel diameter and cultivar Saffron recorded minimum corm weight and corm diameter in all the tested cultivars. The treatment CCC @ 500 ppm was significantly improved the yield parameters and treatment GA3 @ 100 ppm along with Vermicompost @ 80 g/ pot was found inferior among all the treatments.

Desempenho produtivo de genótipos de morangueiro de dia neutro na Serra Gaúcha

O cultivo de morango no período de entressafra, durante os meses de verão, desperta interesse na Serra Gaúcha, devido às condições climáticas favorecerem produções tardias. Para isso, cultivares de dia neutro são utilizadas, já que estas não sofrem interferência do aumento do fotoperíodo para a indução floral. Portanto, a introdução e avaliação de genótipos de dia neutro se configura como uma demanda para os produtores dessa região. Assim, o presente estudo teve como objetivo avaliar a produção de diferentes genótipos de morangueiro de dia neutro na Região da Serra Gaúcha. Foram avaliadas as cultivares Albion, San Andreas e Irma, e as seleções FRF FC 104.01, FRF FC 57.06 e FRF FC 191.02, as quais foram implantadas no município de Farroupilha - RS em maio de 2017, em delineamento inteiramente casualizado contendo quatro repetições, e unidade experimental composta por 10 plantas. Foram avaliadas as variáveis produtivas e de qualidade físico-química das. As cultivares americanas Albion e San Andreas, bem como as seleções italianas FRF FC 104.01 apresentaram maior produção de frutas, estabilidade no tamanho das frutas e prolongamento do ciclo produtivo. Nas condições do estudo, observou-se que a cultivar italiana Irma não expressa o mesmo potencial produtivo observado em seu país de origem.

Effect of rejuvenation pruning on the olive yield of different cultivars in a super-high-density olive orchard

Effect of rejuvenation pruning on the olive yield of different cultivars in a super-high-density olive orchard

Studies on the effect of growth regulator and vermicompost on growth and yield of different cultivars of strawberry (Fragaria x ananassa Duch)

Studies on the effect of growth regulator and vermicompost on growth and yield of different cultivars of strawberry (Fragaria x ananassa Duch)

Comparative study on the biomass yield, chemical composition and in-sacco dry matter degradability of different cultivars of triticale fodder

An experiment was conducted to determine the biomass yield, chemical composition and in-sacco dry matter (DM) degradability of 10 cultivars (WRF-7, TSN-111, TYT-03, TYT-05, TYT-06, TYT-08, TYT-12, ITYN-10, ITYN-14 and ITYN-15) of triticale fodder. The fresh yield of different cultivars of triticale was ranged from 5.03 to 6.85 (t/ha). The organic matter (OM), crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), calcium (Ca) and phosphorus (P) contents of different cultivars of triticale were found 89.62 to 91.78 %, 21.34 to 25.99 %, 23.09 to 29.99 %, 46.77 to 50.80 %, 0.42 to 0.61 % and 0.33 to 0.41 %, respectively. The yield of DM and CP of different cultivars of triticale were varied from 0.77 to 1.44 (t/ha) and 0.193 to 0.351 (t/ha), respectively. Among different triticale cultivars the highest OM and CP contents were found in TYT-12 (91.78 %) and ITYN-10 (25.99 %), respectively. The highest NDF and ADF contents were found in ITYN-14 (50.80 %) and TYT-05 (29.99 %), respectively among different cultivars. The contents of Ca and P in ITYN-10 (0.61 %) and ITYN-14 (0.41 %), respectively were found to be the highest among the cultivars. Potential DM degradability observed in different cultivars of triticale was higher in ITYN-14 and TYT-05 (84.81 and 81.88 %, respectively) compared to others and relatively poor degradability was found in TSN-111 and TYT-03 (60.74 and 61.35 %, respectively). Therefore, it may be concluded that, the cultivar ITYN-10 will be the promising one due to comparatively higher fresh yield, organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), calcium (Ca) and phosphorus (P) content and less acid detergent fibre (ADF) fraction cultivated for fodder production in Bangladesh.http://dx.doi.org/10.3329/bjas.v41i1.11972

Potential for Improving Crop Yields Through Better Water Management in Rainfed Regions

This study was conducted to determine the effect of water supply at critical growth stage of sorghum in Arid Zone Research Institute, D.I. Khan. The results indicated that the yield components and grain yield were significantly affected by water supply. Irrigation applied at heading stage of the crop significantly increased plant height, maturity period, fresh and dry weight of heads plot(-1), 1000 grain weight and grain yield of sorghum irrespective to cultivars. Maximum grain yield of 3319 kg ha(-1) was obtained with irrigation as against 2206 kg ha(-1) obtained from un-irrigated treatments. The plant height, fresh and dry weight of heads plot(-1), 1000 grain weight and grain yield of different cultivars were also different significantly irrespective to irrigation. Maximum grain yield of 2976 kg ha(-1) was produced by the cultivar DS-2000 compared to 2550 kg ha(-1) by DS-97 Yarik. The interaction between irrigation and cultivar as regards yield and yield components of sorghum was non significant. The findings of this study suggested that the grain yield of sorghum can be increased by 50% with irrigation applied at the heading of sorghum.

Dissection of component QTL expression in yield formation in rice

Abstract Yield and its components were investigated by using a population of241 recombinant inbred lines (F 9 RILs) derived from an elite hybridrice cross of Zhenshan 97 · Minghui 63. Quantitative trait loci(QTLs) for causal analysing of yield traits were detected at differentyield component (YC) influences by conditional and unconditionalQTL mapping methods. The number of QTLs significantly affectingyield was different at component-special influence. Some QTLscontrolling yield identified in one component influence were undetect-able at the others. More QTLs for yield could be detected at differentYC influences. It is possible to reveal that causal gene expression foryield could be different at different YC influences. Mapping QTLs forcomponent effects of yield could help us in understanding the nature ofcause-effect traits for the formation of grain yield. Key words: Oryza sativa — quantitative trait loci — recom-binant inbred line — yield — yield componentGrain yield and its four components in cereal crops are alwaysone of the most important target traits in research andbreeding programmes. Faced with the same yield in differentcultivars, there mainly are three model systems of high yieldfrom the view of yield components (YC), such as heavy-panicle, multipanicle and mixture. As Donald (1968) advoca-ted the ideotype concept to describe the potential of enhancingyield by improving the individual component trait, manycomponent analyses have been studied for complex traitsbased on morphological and physiological characterization(Sparnaaij and Bos 1993, Gravois and Helms 1992, Piepho1995, Guo et al. 2002a). In addition, Sidwell et al. (1976)reported that through YC improvement to increase yield (YD)would be most effective because of lower heritability (0.12) forYD (Xiong 1992) and higher heritability for tillers per plant(TP; 0.45) and 1000-grain weight (GW; 0.50) (Li et al. 1998).However, selection for YCs in early segregating generationswas not a highly effective method because of the negativecorrelation between YCs (Li et al. 1998).To solve this contradiction, Backes et al. (1995) and Zhu(1995) suggested that focusing on component gene/quantita-tive trait locus (QTL) for YD should be a more effectiveapproach than looking for QTL for YD directly, because theformer not only allows complex traits to be divided intocomponent QTL that may be under separated and probablysimpler genetic control, but can also exclude the influence ofother components.Because the first restriction fragment length polymorphism(RFLP) map of rice was constructed, hundreds of genes andQTLs have been mapped (Xiao et al. 1995, Lin et al. 1996,Veldboom and Lee 1996, Zhuang et al. 2002). Some yieldQTLs coincided with those for component traits, explainedfrequently as pleiotropic effects or linkage. In these studies, acommon problem associated with the analyses of the datareported so far is that the analysis of QTLs for YD and itscomponents was conducted based on the phenotypic valuesseparately. Although it can provides statistical estimates forthe magnitude of the effects and the proportions of variationexplained, it is nonetheless impossible to detect the componentQTLs controlling complex yield trait based on the phenotypicvalue of yield conditional on the phenotypic value of thiscomponent (Zhu 1995).According to the theory of developmental genetics, genes areexpressed selectively at different time and position (Atchleyand Zhu 1997). Piepho (1995) proposed that the complex yieldcharacter may be regarded as the end-point of a process ofwhich the successive stages are represented by observedprimary characters TP, grains per panicle (GN), percentageseed set and GW. At different YC influences, the yield geneexpressing might behave differentially. It is necessary, there-fore, to understand the component gene expression for yield atdifferent yield factor influences as a basis for quantitative traitmanipulation (Xu 1997). So far, no report has explored thecomponent QTL expression in yield formation in rice. Thesubject of this study is by combining the newly developedstatistical procedures of analysing conditional genetic effects(Zhu 1995, Yan et al. 1998) and the composite intervalmapping method (Zeng 1993, 1994), to dissect the componentQTLs for yield at different component influences, to improveour understanding for gene expression affecting grain yield,and to provide an outline of genetic basis for the cause-resulttraits and useful information for genetic improvement of yieldpotential in rice.

Effect of Leaf Clipping on Plant Growth and Green Fodder Yield of Different Cultivars of Transplant Aman Rice

Effect of Leaf Clipping on Plant Growth and Green Fodder Yield of Different Cultivars of Transplant Aman Rice

The use of grain protein deviation for identifying wheat cultivars with high grain protein concentration and yield

The relationship between grain protein concentration and grain yield in different cultivars of winter wheat was examined in a series of field experiments carried out over three years, in which 13, 12 and 8 cultivars were studied in each year, respectively. The plants were grown at sites located in Shropshire, west-central England, in years 1 and 2, and at three other locations in eastern England in year 3. Above ground plant samples were collected at an thesis and again at maturity, when they were separated into grain and straw, and analysed for dry matter and N content. Analysis of residuals from regression of grain protein concentration on grain yield (grain protein deviation, GPD) showed that some cultivars had a higher grain protein concentration than was predicted from grain yield alone. It was deduced that the capacity to accumulate a higher grain protein concentration than predicted from grain yield is under genetic control and thus may be improved through breeding. Other factors (weight of N accumulated in the biomass at anthesis, weight of N accumulated in the biomass between anthesis and maturity and the concentration of N remaining in the straw at maturity) were added step-wise into the regression to enable statistical analysis of their relative contributions to grain protein. High GPD may be achieved through increased N accumulation after anthesis, combined with efficient re-translocation of vegetative N reserves. The use of GPD provides a selection criteria in wheat breeding programs to screen for increased grain protein concentration without a concurrent grain yield reduction.