Evaluation of Protein Concentration, Amino Acid Profile and Antinutritional Compounds in Hempseed Meal from Dioecious and Monoecious Varieties

Hempseed meal from three dioecious and three monoecious varieties has been evaluated for content and quality of the protein and for the concentration of antinutritional compounds. Hemp seeds were obtained from plants grown in two experimental fields for two consecutive years (2011-2012). For all the varieties, hempseed meal resulted in a rich source of protein (34% mean content) with an amino acid profile extremely rich in arginine and slightly poor in lysine. Differences between dioecious and monoecious varieties were observed in the content of antinutritional compounds. They were more concentrated in monoecious varieties in comparison with those dioecious. The concentration of phytic acid in hempseed meal deserves attention in both groups, being 63 and 75.4 g·kg-1 of dry matter in dioecious and monocieous varieties, respectively. The results show that, besides the recognized value of hemp oil, also the hempseed cake could find application in animal feed as a substitute of other cakes (soybean, rapeseed). From this point of view, the dioecious varieties showing lower contents of antinutritional compounds with respect to the monoecious varieties would be preferred.

Sex-specific responses of tree-ring growth to climate in the dioecious tree Populus cathayana

Aims Radial growth in response to climate has been reported in many trees,but the sex-specific responses of tree-ring growth associated with altitude in dioecious trees are still poorly known.This study aims to examine whether(i)there are sex-related responses of tree-ring growth to climate in dioecious trees;(ii)these responses could be changed with altitude elevation.Methods The tree-ring width and basal area increment(BAI)were measured over the past 30 years(1982-2011),and the sexual differences in relationship between BAI and time span and correlations between ring width and climatic factors were investigated in Populus cathayana trees at two altitude sites(1,450 m and 1,750 m a.s.l.)in Xiaowutai Mountain,Hebei,north China.Important Findings The BAI was increased over the past 30 years.Trees at high-altitude sites had significantly lower mean ring width and mean BAI than those trees at low-altitude sites(P<0.001).In addition,sexual dif-ferences in tree-ring growth and its response to climate were more pronounced by altitude elevation.Male trees had a significantly larger mean ring width and mean BAI than did females at high-alti-tude sites,whereas no significant sexual differences in these traits were detected at low-altitude sites.Female trees were sensitive to previous October-November temperatures at high altitude but to current February and April precipitation at low altitude(P<0.05),whereas male trees were sensitive to current June temperature at high altitude but to January precipitation at low altitude(P<0.05).Our results indicated that the responses of tree-ring growth to cli-mate are sex dependent and can be changed with altitude elevation.

Intersexual differences in leaf size and shape in dioecious Adriana tomentosa

Aims Leaf size and shape as objects of natural selection can play adaptive roles,and can change with the age of leaves.They can differ between sexes in dioecious species,and in most cases,females have larger leaves.Previous studies showed that sexes of Adriana tomentosa differed in their leaf lobing.In this study,we investigated whether there were other differences between sexes in leaf size,shape and ecophysiology,and if those differences were connected with adaptations and reproductive roles in the sexes of A.tomentosa.Methods Physical and chemical features of young and old leaves originating from female and male A.tomentosa plants growing in two disjunct populations in eastern Australia were measured.We determined leaf area,perimeter length,serration,circularity,aspect ratio(AR),roundness and the ecophysiological factors:specific leaf area,dry matter content,leaf moisture,relative water content,δ^(13)C,δ^(15)N isotope compositions,carbon and nitrogen contents and C:N ratio.Leaf lobing,the degree of lamina damage and the content of photosynthetic pigments were also determined.Important Findings In both populations studied,the sex of plants significantly influenced almost all parameters connected with leaf morphology such as area,perimeter length,circularity,AR and roundness.Contrary to expectations,males from both populations had a greater leaf area that was independent of leaf age.Male leaves were more lobed with a longer perimeter,but they were less elongated and less serrated.Only small differences between female and male leaves were observed for the ecophysiological factors.The degree of leaf damage differed between sexes but also with population.Differences between sexes in leaf area and shape were not compensated by measured ecophysiological factors.However,leaf area may be compensated by other ecophysiological mechanisms related to leaf morphology,because females had greater leaf serration in comparison to males despite the smaller leaf area.

Rhizosphere bacterial communities and soil nutrient conditions reveal sexual dimorphism of Populus deltoides

Sexual dimorphism of plants shapes the diff erent morphology and physiology between males and females.However,it is still unclear whether it infl uences belowground ecological processes.In this study,rhizosphere soil of male and female Populus deltoides and bulk soil were collected from an 18-year plantation(male and female trees mix-planted)and grouped into three soil compartments.Soil carbon(C),nitrogen(N)and phosphorus(P)levels were determined,and soil bacterial communities were analyzed by high-throughput sequencing.The results showed the less total carbon and total organic carbon,the more nutrients(available phosphorus,nitrate nitrogen and ammonium nitrogen)available in the rhizosphere soils of female poplars than soils of males.However,α-diversity indices of the rhizosphere bacterial communities under male plants were signifi-cantly higher.Principal component analysis showed that the bacterial communities were signifi cantly diff erent between the male and female soil compartments.Further,the bacterial co-occurrence network in soil under male trees had more nodes and edges than under females.BugBase analysis showed the more functional bacteria taxa related to biofi lm formation and antioxidation under males.The results indicate that soils under male poplars had more diverse and more complex co-occurrence networks of the rhizosphere bacterial community than soils under female trees,implying that male poplars might have better environmental adaptability.The study provides insight into the diff erent soil-microbe interactions of dioecious plants.More details about the infl uencing mechanism of sexual dimorphism on rhizosphere soil bacterial communities need to be further studied.

Transcriptome analysis of Idesia polycarpa Maxim. var vestita Diels fl owers during sex differentiation

Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mechanism of sex diff erentiation in fl ower development,we conducted the transcriptome profi les of male and female fl owers at early,metaphase and late developmental stages.Approximately 123,335 unigenes with a total length of 83,996 Mb and an average length of 168 bp were assembled.The unigenes were blasted into Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,GO databases.Homology analysis demonstrated that I.polycarpa and black cottonwood had the highest homology with the alignment of 92,871 sequences.This study identifi ed 80 groups of transcription factor families with a total of 1475 unigenes,mainly including MYB,WRKY,AP2 and bHLH transcription factor families.KEGG pathway analysis showed that the expression of numerous plant hormones(cytokinin,gibberellin and ethylene)and fl avonoid biosynthesis pathway were diff erent at various stages of female and male fl ower development.In addition,a number of unigenes associated with fl owering were identifi ed which were key genes associated with photoperiodic,vernalization,thermosensory,gibberellin,and autonomic pathways.The results show that I.polycarpa fl oral organ development was in accordance with the ABCDE model,in which the down-regulation of the B gene family might aff ect stamen fertility in late stages of female fl ower development.qRTPCR experiments validated that the expression patterns of 15 unigenes were consistent with those in RNA-seq results.The results highlight a central role for plant sex identifi cation in seedling production and a sex-determining mechanism for dioecious plants.In addition,the transcriptome data provided a theoretical basis for I.polycarpa genetic diversity analysis and molecular-assisted breeding.

Karyological and Electrophoretic Distinction between Sexes of <i>Trichosanthes bracteata</i>

Chromosome studies and soluble protein profiles, fractionated by reducing and non-reducing SDS-PAGE, were carried out in dioecious Trichosanthes bracteata. Somatic chromosome no. 2n = 22 was recorded in both sexes. The karyotype of male and female plant shows high homogeneity and the absence of any heteromorphic pair of chromosomes negates the possibility of XY mechanism. Soluble protein profiles from the tuberous roots of the male and female plants, fractionated by reducing SDS-PAGE, did not show any qualitative distinction. Whereas the protein profile in non-reducing SDS-PAGE reveals a clear distinction when compared on a single gel. The difference is marked by the presence of a disulphide linked tertiary or folded protein at 19 k D region detected in male sex. However, at the level of primary structure the qualitative expression is similar indicating a common ancestry.

Morphological and physiological differences in heteromorphic leaves of male and female Populus euphratica Oliv.

Leaf traits can directly reflect the adaptation strategies of plants to the environment.However,there is limited knowledge on the adaptation strategies of heteromorphic leaves of male and female Populus euphratica Oliv.in response to individual developmental stages(i.e.,diameter class)and canopy height changes.In this study,morphological and physiological properties of heteromorphic leaves of male and female P.euphratica were investigated.Results showed that both male and female P.euphratica exhibited increased leaf area(LA),leaf dry weight(LDW),leaf thickness(LT),net photosynthetic rate(P_(n)),transpiration rate(T_(r)),stomatal conductance(g_(s)),proline(Pro),and malondialdehyde(MDA)concentration,decreased leaf shape index(LI)and specific leaf area(SLA)with increasing diameter and canopy height.Leaf water potential(LWP)increased with increasing diameter,LWP decreased significantly with increasing canopy height in both sexes,and carbon isotope fraction(δ^(13)C)increased significantly with canopy height in both sexes,all of which showed obvious resistance characteristics.However,males showed greater LA,LT,P_(n),T_(r),and Pro than females at the same canopy height,and males showed significantly higher LA,SLA,LT,P_(n),T_(r),g_(s),and MDA,but lower LWP and δ_(1)3C than females at the same canopy height,suggesting that male P.euphratica have stronger photosynthetic and osmoregulatory abilities,and are sensitive to water deficiency.Moreover,difference between male and female P.euphratica is closely related to the increase in individual diameter class and canopy height.In summary,male plants showed higher stress tolerance than female plants,and differences in P_(n),g_(s),T_(r),Pro,MDA,δ_(13)C,and LWP between females and males were related to changes in leaf morphology,diameter class,and canopy height.The results of this study provide a theory for the differences in growth adaptation strategies during individual development of P.euphratica.

Assessing Anthropogenic Pressure and Its Impact on Hippophae salicifolia Pockets in Central Himalaya,Uttarakhand

Natural habitat ofHippophae salicifolia in Central Himalaya is continuously being degraded due to habitat destruction and harvesting. Although logging is prohibited, habitat destruction has increased because of regular road construction, repairing and broadening activities. In addition, Hippophae resources are continuously being harvested by lopping （both partial and complete） for fuelwood, fodder and fruits in higher Himalayan region. This paper presents a detailed analysis of relationship between density, demographic structure, and harvesting of H. salicifolia growing pockets in the five major valleys （Gangotri, Yamunotri, Niti, Mana and Bhyundhar） of Uttarakhand in Central Himalaya, India. A total of 12o quadrats were laid randomly to study population structure, regeneration, sex ratio and lopping using quadrats of lOO m2 （a4 in each valley） in Hippophae growing patches. Our study shows that the density, size distribution, and regeneration of Hippophae vary considerably among the major valleys. Trees in the Yamunotri valley have the highest density of large trees but the lowest density of seedlings. In contrast, there are few large trees but many seedlings in the Mana valley. The number and size of lopped trees also varied among the valleys. Lopping was greatest in Bhyundhar （11.4%） and Yamunotri （19.7%） and least in Niti （3.9%）. The size of lopped trees differed substantially as well. In Bhyundhar, the largest trees were taken while saplings were taken in Yamunotri. Our study revealed that unsustainable harvesting from plants for fuel, fencing and fruits along with road broadening activities in Central Himalaya are the main cause ofhabitat destruction. Our research highlights the urgent need for in-situ and ex-situ conservation of Hippophae salicifolia so that it＇s potential can be harnessed sustainably by rural hill societies for their socio-economic development.

<i>Conocephalum conicum</i>(L.) Dumort: A Case of Unique Reproductive Biology

This paper reports spore-elater ratio per capsule in three populations of Conocephalum conicum collected from different regions of Jammu and Kashmir (Doda, Ladakh and Bhaderwah). Spore-elater ratio came out to be 0.40-0.43:1, far less than expected for Marchantialian taxa. The ratios thus obtained were compared with that present in herbarium specimen collected in 1958 from Kyushu. The ratios have remained constant since many decades, thereby indicating that the sex-ual reproduction has lesser role to play in the propagation of this species.

Sex-specific strategies of resource utilization and determining mechanisms of Hippophae rhamnoides in response to community succession

The dioecious plant,Hippophae rhamnoides,is a pioneer species in community succession on the Qinghai-Tibet Plateau(QTP),plays great roles in various ecosystem services.However,the males and females of the species differ both in their morphology and physiology,resulting in a change in the ratio of male to female plants depending on the environment.To further explore the functional traits critical to this sex-based distinctive response in the alpine grassland,we have surveyed the sex ratios,measured their photosynthetic parameters,height,leaf area and biomass allocation.The results showed that(i)The males had higher Pn,light saturation point,apparent quantum efficiency,A_(max) and lower water-use efficiency(WUE),which exhibited higher utilization efficiency or tolerance to strong light,while the females indicated higher utilization efficiency for low light and water.And it showed sex-specific biomass allocation patterns.(ii)H.rhamnoides populations across the successional stages all showed a male-biased sexual allocation,which was closely related to sex-specific WUE,Pn,root biomass/total biomass and root-crown ratio.(iii)The leaf traits of H.rhamnoides changed from higher N_(area),P_(area) and leaf mass per area in the early and late to lower in the middle,which meant they moved their growth strategy from resource rapid acquisition to conservation as the succession progressed.(iv)The increasing soil total phosphorus mostly contributed to regulating the sex bias of populations and variations of traits during the succession.The results are vital for the management of grassland degradation and restoration due to shrub encroachment on the QTP.

The sexual dimorphism displayed by the roots of mulberry(Morus alba)saplings depends on the sex of the neighboring plants

Aims Dioecious plants present sexual dimorphism,but how the root traits and nutrient uptake of female and male plants in dioecious species response to the sexual identity change of the neighbor plants are poorly understood.Methods Mulberry(Morus alba L.),a dioecious plant widely distributed in China,was employed in our study.Male and female plants were grown with neighbors of the same and opposite sex for 3 months.At harvest,the root anatomy,root morphology,nutrient concentrations and biomass accumulation were measured.Important Findings When grown with the opposite sex,the males showed decreases in root xylem size,biomass of root and stem and increases in root N,P and K concentrations compared with grown with the same sex.By contrast,females showed significant increases in xylem size,fine root system(e.g.fine root length,root surface area and root volume),root carbon isotope composition(δ13C)and root N,P and K concentrations.The changes in theδ13C and N,P and K concentrations in male and female plants were associated with the changes of root traits.These results demonstrated that the sexual identity of the neighboring plants affected root anatomy and morphology of female and male mulberry plants.Meanwhile,the responses of female and male plants to the sex change of the neighboring plants showed sexual dimorphism,which influenced water-use efficiency and resource acquisition.These findings are important for understanding the population dynamics of other dioecious species in forestry and natural systems.