QTL analysis of leaf photosynthetic rate and related physiological traits in rice(Oryza sativa L.)

Photosynthesis is one of the most important factors that influence the biomass and yield. Recently, more attention has been paid to genetic study on rice photosynthesis and rice breeding for the physiological traits related to high efficient photosynthesis. Chlorophyll content, stomatal resistance, and transpiration rate were very important physiological traits related to photosynthesis. But until now, no genetic study on these traits has been reported. A DH population derived from anther culture of ZYQ8/JX17, a typical indica/japonica hybrid was developed,

Leaf stable carbon isotope composition in Picea schrenkiana var. tianschanica in relation to leaf physiological and morphological characteristics along an altitudinal gradient

To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.

Effects of Potassium-Solubilizing Bacteria on Growth, Antioxidant Activity and Expression of Related Genes in Fritillaria taipaiensis P. Y. Li

This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiologicaland biochemical characteristics. At present, some studies have only studied the rhizosphere microbialcommunity characteristics of F. taipaiensis and have not discussed the effects of different microbial species on thegrowth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria toconduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compoundinoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilizedsoil functioning as the control group. The results reveal that intercellular CO_(2) concentration (Ci), stomatal conductance(Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited anincrease in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase(SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD,and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. Theinoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. taipaiensis.The composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis,manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuableinsights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.

Influence of Mn and Fe Counteraction on Rice（OryzasativaL．）Oranging Physiological Disease

Mn and Fe are two important micronutrients of paddy soils derived from red earths. Rice (Oryza sativa L.) or-anging physiological disease in newly reclaimed red earths is related to Fe toxicity. There have been considerable stud-ies on Mn and Fe counteraction, but influence of Mn and Fe counteraction on rice oranging physiological disease stillremains unknown.This paper is to study, using two soils from USA and China respectively, the relationship between Mn and Fecounteraction and the physiological disease. Analysis for water soluble and extractable Fe and Mn showed thatMn/ Fe ratios of the red earths were lower than those of the paddy soils. Fertilizing with Mn raised Mn/ Fe and re-duced oranging leaves, improved growth and increased yields. Analysis with electron probe showed that Mn treat-ment had less Fe deposit in root epidermis and more Ca and Si in roots.The results indicated that fertilizing with Mn could correct Fe toxicity. How to apply Mn and Fe counteractionin practice is worth further studying .

Crown and leaf traits as predictors of subtropical tree sapling growth rates

Aims Growth rates of plants are driven by factors that influence the amount of resources captured and the efficiency of resource use.In trees,the amount of light captured and the efficiency of light use strongly depends on crown characteristics and leaf traits.Although theory predicts that both crown and leaf traits affect tree growth,few studies have yet to integrate these two types of traits to explain species-specific growth rates.Using 37 broad-leaved tree species of subtropical forests in SE China,we investigated how interspecific differences in wood volume growth rates were affected by crown and leaf traits.We tested the hypotheses that(i)larger crown dimensions promote growth rates,(ii)species-specific growth rates are positively related to leaf stomatal conductance,leaf water potential and leaf chemical components,and negatively related to leaf C/N and leaf toughness and(iii)the two sets of traits better explain growth rates in combination than either alone.Methods Our study was conducted in a large-scale forest Biodiversity and Ecosystem Functioning experiment in China(BEF-China),located in a mountainous region in Jiangxi Province.We related 17 functional traits(two crown dimension and three crown structure traits;six physiological and six morphological leaf traits)to the mean annual growth rate of wood volume of young trees of the studied species.Interrelationships between crown and leaf traits were analyzed using principal component analysis.Simple linear regression analysis was used to test the effect of each trait separately.We used multiple regression analysis to establish the relationship of growth rate to each set of traits(crown traits,physiological and morphological leaf traits)and to the combination of all types of traits.The coefficients of determination(R^(2)_(adj))of the best multiple regression models were compared to determine the relative explanatory power of crown and leaf traits and a combination of both.Important Findings The species-specific growth rates were not related to any of the single crown traits,but were related positively to leaf stomatal conductance and leaf water potential individually,and negatively to leaf toughness,with approximately 13%variance explained by each of the traits.Combinations of different crown traits did not significantly explain the species-specific growth rates,whereas combinations of either physiological or morphological leaf traits explained 24%and 31%,respectively.A combination of both crown and leaf traits explained 42%of variance in species-specific growth rates.We concluded that sets of traits related to carbon assimilation at the leaf-level and to overall amount of leaves exposed at the crown-level jointly explained species-specific growth rates better than either set of traits alone.