Long-term pineapple monoculture severely degrades soil in tropical regions, necessitating sustainable remediation strategies. This study evaluated the effectiveness of crop rotation and organic fertilization in improving soil health and productivity through a field experiment in a decade-long continuously cropped pineapple orchard, with four treatments: continuous pineapple (PP, control); PP with 30 % organic fertilizer substitution (OP); Alpinia officinarum-pineapple rotation (GP); banana-pineapple rotation (BP). Soil health was evaluated using three metrics: the soil quality index (SQI) derived from conventional biochemical indicators, and soil multi-functionality (SMF) based on seven enzymatic activities, and microbial community structure via phospholipid fatty acid (PLFA) profiling. Microbial metabolic limitation was determined via extracellular enzyme stoichiometry. Compared to PP, both remediation strategies significantly alleviated microbial phosphorus (P) limitation, increasing EEAN:P by 12.4-16.6 % and reducing the vector angle by 20.1-27.7 %. Consequently, they enhanced microbial abundance (PLFA increased 30.9-84.1 %) and diversity, with increases in SQI (21.2-47.4 %), SMF (26.8-45.7 %), and pineapple yield (9.3-25.5 %). Crop rotation, particularly BP, consistently outperformed organic fertilization across these metrics-e.g., BP rotation increased total PLFA by 84.1 %, markedly exceeding the 30.9 % increase under OP. Structural equation modeling (SEM) analysis confirmed a critical pathway whereby P limitation alleviation enhanced microbial abundance and SMF, directly boosting yield. Thus, while both strategies were beneficial, crop rotation was superior, with BP most improving soil health and productivity. These findings inform sustainable tropical agriculture and soil health indicator selection.

Surface energy partitioning governs canopy thermal conditions and water use by determining how available energy is dissipated as latent versus sensible heat. In tropical and subtropical croplands, compound heat–drought events increase atmospheric evaporative demand, yet crassulacean acid metabolism (CAM) crops may respond differently from C3/C4 systems because daytime stomatal regulation constrains transpiration. Here we quantify subdaily energy partitioning in a subtropical CAM pineapple field in southern China using Bowen-ratio energy balance observations. Net radiation (Rn), soil heat flux (G), and vertical gradients of temperature and vapor pressure were used to estimate sensible (H) and latent (LE) heat fluxes and to compute available energy (A = Rn− G). To diagnose the coupling relationship between atmospheric demand and water supply, hourly data were classified into four weather types (WT4) using median thresholds of Rn and vapor pressure deficit (VPD): LRn–LVPD (low Rn, low VPD), LRn–HVPD (low Rn, high VPD), HRn–LVPD (high Rn, low VPD), and HRn–HVPD (high Rn, high VPD). Soil water content (SWC) at a depth of 20 cm was further classified into three soil moisture states (SWC3) using percentiles (Dry, Normal, and Wet). Scenario medians and valid-hour counts were used to summarize LE/A, H/A, and G/Rn, complemented by Bowen ratio (β = H/LE) as an integrative indicator of sensible versus latent heat partitioning. The results showed that energy partitioning was dominated by compensation between LE/A and H/A, while G/Rn remained small. LE/A was consistently lower under HRn–HVPD than under LRn–LVPD across soil-moisture states. Under LRn–LVPD, LE/A was 0.47 in Dry and Normal and increased to 0.56 in Wet; under HRn–HVPD it ranged from 0.26 (Dry) to 0.37 (Wet). Moisture effects were demand dependent: within HRn–HVPD, LE/A increased by 0.11 from Dry to Wet, whereas the LRn–LVPD Dry-to-Wet increase was 0.09. β responses reinforced this interaction. Under Dry conditions, β increased with VPD and remained high at high VPD, whereas under wet soils β was lower and tended to level off. Under HRn–HVPD, β declined steeply as SWC increased over 0.23–0.27 m3 m-3, then approached a plateau near 1.7; under non-HRn–HVPD conditions β showed weaker dependence and plateaued near 2.0. Composite daytime patterns further showed sustained H dominance under HRn–HVPD–Dry, while HRn–HVPD–Wet shifted partitioning toward higher LE. These results demonstrate that atmospheric demand sets a strong constraint on daytime evaporative cooling in this CAM pineapple system, and that soil water supply enhances latent heat dissipation most effectively under high-demand conditions, thereby informing model parameterization and targeted water management.

Pineapple (Ananas comosus (L.) Merr.), a typical Crassulacean acid metabolism (CAM) crop, exhibits remarkable drought tolerance; however, the concurrent responses of photosystem II (PSII) and photosystem I (PSI) under drought stress remain unclear. In this study, three pineapple cultivars (‘MD-2’, ‘Tainong21’, and ‘Paris’) were subjected to progressive drought stress (mild, moderate, and severe) followed by rewatering, PSII energy allocation and PSI limitation responses was evaluated using Dual-PAM chlorophyll fluorescence measurements. Drought stress significantly altered photosynthetic energy partitioning among cultivars, as reflected by consistent changes in ETR(II), NPQ, and Y(NO) across drought stages. Under mild drought, ‘Tainong21’ showed an early reduction in ETR(II) accompanied by relatively elevated NPQ, whereas ‘Paris’ exhibited a comparatively conservative response by reducing photochemical activity under moderate drought. In contrast, ‘MD-2’ maintained relatively higher ETR(II) together with stable NPQ throughout drought progression and showed the strongest recovery after rewatering. Across cultivars, severe drought was associated with decreased NPQ and increased Y(NO). PSI-related parameters showed comparatively smaller variation, with stable Y(ND) but increased Y(NA) under severe drought. Linear mixed-effects model analysis further indicated that the estimated cyclic electron flow (CEF), used as a proxy, exhibited a significant cultivar × drought interaction under high light conditions. Most fluorescence parameters partially recovered after rehydration, suggesting that the observed limitations were largely reversible at the functional level. Overall, these results demonstrate cultivar-specific photosystem response patterns under drought and provide a physiological basis for fluorescence-based phenotyping and drought-tolerance screening in CAM crops.

Excessive use of chemical fertilizers has caused soil degradation and reduced pineapple yields, threatening sustainable cultivation. A potential remedy involves partially substituting chemical fertilizers with organic fertilizers. Liquid organic fertilizers are gradually replacing traditional solid organic fertilizers due to their higher efficiency and easier application. However, there is still a lack of comprehensive research on how liquid organic fertilizers improve soil conditions and enhance yield in pineapple plantations. To address this gap, a four-year field experiment (2019-2023) compared three treatments: chemical fertilizers (CK, control), partial solid organic substitution (SOF), and partial liquid organic substitution (LOF). The study evaluated soil carbon (C), nitrogen (N), and phosphorus (P) stoichiometry, C pool dynamics, microbial community structure, and biomass production across two pineapple growth cycles. Results showed that LOF significantly improved soil organic carbon (SOC), labile C, and the C pool management index (CPMI) compared to CK and SOF. Additionally, LOF enhanced the soil quality index (SQI), microbial total phospholipid fatty acids (PLFAs), Shannon diversity index, and the monounsaturated/saturated PLFAs ratio. LOF increased SOC by 5.9-15.7 %, labile C by 30.7-53.4 %, and CPMI by 46.0-73.4 %. It also enhanced SQI by 21.9-24.7 %, microbial total PLFAs by 41.0-79.1 %, and the monounsaturated/saturated PLFAs ratio by 21.4-65.4 %. Furthermore, LOF boosted biomass and yield by 41.3-43.9 % and 13.7-35.9 %, respectively, while SOF excelled in enhancing SOC sequestration within macroaggregates (>0.25 mm). Correlation analysis and structural equation modeling revealed that LOF enhances soil biological fertility by optimizing SOC quantity, quality, and the C:P stoichiometric ratio, with CPMI playing a central role in improving pineapple productivity. In conclusion, LOF has demonstrated significant potential in improving soil quality and pineapple productivity, serving as a lightweight, efficient, and sustainable alternative to chemical fertilizers. It provides a reference for optimizing fertilization strategies and promoting the sustainable development of pineapple cultivation.

This study aims to understand the characteristics and distribution patterns of soil phosphorus (P) forms in the tropical high-P orchards under cover cropping and to explore the biotic and abiotic factors driving the changes in P forms. The study collected three kinds of soil (clean tillage [CK, control], Stylosanthes guianensis cover [SC, legume], and Cynodon dactylon (L.) Pers. cover [CC, grass]) from a mango orchard and determined P forms in the water-stable aggregates and bulk soil, analyzed the environmental factors and the structure of the bacterial-fungal community. Compared to CK, SC and CC have a significant positive influence on the forms and distribution of soil P, increase the content of organic P (Org-P) and certain inorganic P forms (Al-P and Fe-P), and enhance the content of P within macroaggregates (>0.25 mm), thereby maintaining total P (TP) and Olsen-P in the top 30 cm of soil, particularly for the SC treatment. SC and CC also improved acid phosphatase (ACP), and water-stable aggregates while decreasing bulk density (BD) and exchangeable aluminium (Al-e) in the topsoil (0-15 cm). Redundant and Pearson analysis revealed these factors significantly affected soil P availability. Moreover, SC and CC increased the relative abundance of Nitrospira, Candidatus-Udaeobacter, Pseudolabrys, and ADurb.Bin063-1 in the topsoil (0-15 cm), and decreased the relative abundance of Occallatibacter. Redundant and Pearson analysis indicated that these bacterial communities are likely associated with the availability of P. Overall, cover cropping promoted the transformation and distribution of P forms by altering the physical, chemical, and biological environment of the soil, which was beneficial for the sustainable P management in tropical high-P soils. This research offers practical insights into the use of cover crops as a tool for enhancing soil health and sustainable P management in tropical high-P orchards.

It is of great importance to study the changes in reference evapotranspiration (ET0) and the factors that influence it to ensure sustainable and efficient water resource utilization. Daily ET0 data calculated using the Penman–Monteith method from 37 meteorological stations located within Guangdong Province in the humid zone of southern China from 1960 to 2020 were analyzed. The trend analysis and Mann–Kendall test were used to analyze the time series changes in ET0 and major climatic factors (air temperature (T), relative humidity (RH), sunshine duration (SD), and wind speed (u2)) for over 61 years. Sensitivity and contribution analyses were used to evaluate the driving factors of ET0. The main findings of the study are as follows: (1) the trend in average annual ET0 time series in Guangdong slightly increased at a trend rate of 1.61 mm/10a over the past 61 years, with most stations experiencing an increase in ET0. During the same period, air temperature significantly increased, while RH and SD decreased; u2 also decreased. (2) Sensitivity analysis showed that ET0 was more sensitive to RH and T than SD and u2, with ET0 being most sensitive to RH in spring and winter and T in summer and autumn. (3) The contribution analysis showed that T was the dominant factor for ET0 variation in Guangdong, followed by SD. SD was found to be the dominant factor in ET0 changes in areas where the “evaporation paradox” occurred, as well as in spring and summer. The study concludes that the climate in Guangdong became warmer and drier over the past 61 years, and if the current global warming trend continues, it will lead to higher evapotranspiration and drought occurrence in the future.

Phosphorus (P) is one of the mineral nutrients that exhibit a high propensity for fixation in soil. Interplanting herbage is considered as a mode to produce green orchards that can effectively improve soil quality and ecological function. To assess the impacts of intercropping herbage on the morphological characteristics and availability of P in the acidic soil of mango ( Mangifera indica L . ) orchards, three kinds of soil (clean tillage [CK], intercropping Stylosanthes guianensis [SC], and intercropping Cynodon dactylon (L.) Pers. [CC]) were collected from a tropical mango orchard during a 4-year field study. This study determined the morphological characteristics of P in the water-stable aggregates and bulk soil, analysed the bacterial-fungal community structure and diversity, and evaluated the correlation between the environmental factors, P fractions, and microbial communities. This study showed that interplanting S. guianensis and C. dactylon enhanced the availability of soil P by increasing the organic P, and partial inorganic P (Al-P and Fe-P) in the 0.25–2 mm aggregate compared with the CK. In addition, interplanting herbage also altered the structure and diversity of soil bacterial-fungal community. A Mantel analysis revealed that the structure of the bacterial community had a greater influence on the P fractions compared to bacterial α-diversity. The fungal community had minimal impact on the P fractions. Interestingly, the Nitrospira , Candidatus-Udaeobacter , Pseudolabrys , MND1 , Tepidisphaera , Aquicella , unclassified-Vicinamibacterales , ADurb.Bin063‒1 , Humicola , and Purpureocillium contribute to the availability of soil P. In conclusion, interplanting herbage favors the activation of soil P in the acidic soil of mango orchards.

为实现甘蔗新品种耐旱性的早期评价鉴定,加快甘蔗耐旱育种进程.本研究以生产上已有的耐旱品种新台糖 22 号与非耐旱品种新台糖 16 号作为对照,对 2个甘蔗新品种热甘 1号与桂柳 07150 开展盆栽模拟干旱与田间干旱试验,测定叶绿素荧光特性与经济性状.结果表明,在桶栽模拟干旱胁迫下,只有新台糖 16 号的潜在最大光能利用效率 Fv/Fm显著下降,非调节性能量耗散 Y(NO)则表现为:桂柳07150＜热甘 1号＜新台糖 22 号＜新台糖 16 号,而Y(NPQ)和PARsat均表现为:2个新品种＞新台糖 22号＞新台糖 16 号.上述结果表明在土壤相对含水量rSWC降至 60%时,只有新台糖 16 号出现实质性光损伤,2 个新品种的光保护能力优于新台糖 22 号.综上,将供试品种的耐旱性由强到弱的排序为:桂柳 07150＞热甘 1号＞新台糖 22 号＞新台糖 16 号.田间观测结果表明,相同干旱胁迫程度下,Jmax与单茎重、产量、田间锤度及有效茎数均呈正相关,据此推论较强的光合能力是桂柳 07150 的单茎重与热甘 1 号的有效茎数显著高于新台糖 22 号的重要因素,并最终确定 2个新品种的产量与田间锤度显著高于新台糖 22 号,进一步验证了 2个甘蔗新品种应对干旱的能力优于新台糖 22 号.综上,叶绿素荧光技术能够在甘蔗新品种耐旱性的早期快速鉴定评价中发挥重要作用.

Mulching management is one of the most effective measures to alleviate soil erosion and improve soil quality in clean tillage orchards. However, the effects of mulching management patterns on carbon and nitrogen distribution have not been fully investigated, and water infiltration in the system is still unclear. This study aims to clarify the effects of mulching management on soil aggregates, carbon and nitrogen distribution, and water infiltration in subtropical clean tillage orchards in China. In this study, we focused on a typical latosol mango orchard in China subject to subtropical monsoon climate conditions. Traditional bare soil cleaning tillage management was applied to the control area, and two treatments (i.e., Stylosanthes guianensis covering and horticultural ground fabric mulching) were set up. Soil aggregates and aggregate-associated carbon and nitrogen were investigated in three soil depths (0–15 cm, 15–30 cm, and 30–45 cm). The water content was monitored in 0–100 cm soil layer. Compared to clean tillage (CK), horticultural ground fabric mulching (GC) and Stylosanthes guianensis covering (SC) significantly improved the stability of soil aggregates and the proportion of > 0.25-mm water-stable aggregates in the three soil layers. And SC increased the SOC contents by 11.1% and 23.2% in the 0–15 cm and 15–30 cm soil layer while increased the TN contents by 8.3 and 24.6%, respectively. Moreover, it increased the SOC stock by 18.2% in the 15–30 cm soil layer. GC only increased 17.4% in SOC content in the 15–30 cm layer but no significant changes on SOC stocks, TN contents, and stocks in the three soil layers. However, GC is conducive to the water storage in the 0–100 cm soil layer and infiltration into the > 100 cm soil layer compared to SC. In conclusion, covering Stylosanthes guianensis seems to have the best enhancing effect on soil quality in subtropical orchards but restriction the water into the > 100 cm soil layer. And small macroaggregates (0.25‒2 mm) favored the enhancement of the SOC and TN contents. The findings may be useful for clean tillage orchard management in subtropical China.

Sugarcane is the major sugar-producing crop worldwide, and hybrid F1 populations are the primary populations used in breeding. Challenged by the sugarcane genome’s complexity and the sucrose yield’s quantitative nature, phenotypic selection is still the most commonly used approach for high-sucrose yield sugarcane breeding. In this study, a hybrid F1 population containing 135 hybrids was constructed and evaluated for 11 traits (sucrose yield (SY) and its related traits) in a randomized complete-block design during two consecutive growing seasons. The results revealed that all the traits exhibited distinct variation, with the coefficient of variation (CV) ranging from 0.09 to 0.35, the Shannon-Wiener diversity index (H′) ranging between 2.64 and 2.98, and the broad-sense heritability ranging from 0.75 to 0.84. Correlation analysis revealed complex correlations between the traits, with 30 trait pairs being significantly correlated. Eight traits, including stalk number (SN), stalk diameter (SD), internode length (IL), stalk height (SH), stalk weight (SW), Brix (B), sucrose content (SC), and yield (Y), were significantly positively correlated with sucrose yield (SY). Cluster analysis based on the 11 traits divided the 135 F1 hybrids into three groups, with 55 hybrids in Group I, 69 hybrids in Group II, and 11 hybrids in Group III. The principal component analysis indicated that the values of the first four major components’ vectors were greater than 1 and the cumulative contribution rate reached 80.93%. Based on the main component values of all samples, 24 F1 genotypes had greater values than the high-yielding parent ‘ROC22’ and were selected for the next breeding stage. A rapid sucrose yield estimation equation was established using four easily measured sucrose yield-related traits through multivariable linear stepwise regression. The model was subsequently confirmed using 26 sugarcane cultivars and 24 F1 hybrids. This study concludes that the sugarcane F1 population holds great genetic diversity in sucrose yield-related traits. The sucrose yield estimation model, ySY=2.01xSN+8.32xSD+0.79xB+3.44xSH−47.64, can aid to breed sugarcane varieties with high sucrose yield.

Selections of drought-tolerant cultivars and drought-stress diagnosis are important for sugarcane production under seasonal drought, which becomes a crucial factor causing sugarcane yield reduction. The main objective of this study was to investigate the differential drought-response strategies of drought-resistant (‘ROC22’) and -susceptible (‘ROC16’) sugarcane cultivars via photosynthetic quantum efficiency (Φ) simulation and analyze photosystem energy distribution. Five experiments were conducted to measure chlorophyll fluorescence parameters under different photothermal and natural drought conditions. The response model of Φ to photosynthetically active radiation (PAR), temperature (T), and the relative water content of the substrate (rSWC) was established for both cultivars. The results showed that the decreasing rate of Φ was higher at lower temperatures than at higher temperatures, with increasing PAR under well-watered conditions. The drought-stress indexes (εD) of both cultivars increased after rSWC decreased to the critical values of 40% and 29% for ‘ROC22’ and ‘ROC16’, respectively, indicating that the photosystem of ‘ROC22’ reacted more quickly than that of ‘ROC16’ to water deficit. An earlier response and higher capability of nonphotochemical quenching (NPQ) accompanied the slower and slighter increments of the yield for other energy losses (ΦNO) for ‘ROC22’ (at day5, with a rSWC of 40%) compared with ‘ROC16’ (at day3, with a rSWC of 56%), indicating that a rapid decrease in water consumption and an increase in energy dissipation involved in delaying the photosystem injury could contribute to drought tolerance for sugarcane. In addition, the rSWC of ‘ROC16’ was lower than that of ‘ROC22’ throughout the drought treatment, suggesting that high water consumption might be adverse to drought tolerance of sugarcane. This model could be applied for drought-tolerance assessment or drought-stress diagnosis for sugarcane cultivars.

The production and breeding of peanuts was restricted by the frequently extreme climatic conditions in Guangdong province, China. To understand the influence of drought and pluvial climates on peanut traits and yield, a phenotypic investigation of seventy peanut cultivars was conducted from 2018 to 2022; comprehensive field meteorological data collection, and typical drought (2021) and pluvial (2022) climates were recorded. The results revealed that the cultivars achieved the highest single plant pod weight (SPPW) and single plant seed weight (SPSW) of 61.03 g and 45.84 g, respectively, in drought conditions, followed by the control, and finally the pluvial. The SPPW, SPSW and eight agronomy traits exhibited significant differences across the different climatic conditions. Correlation analysis revealed the yield traits and key yield-related traits were positively or negatively correlated with soil water content (SWC), total global radiation (TGR), total precipitation (TP) and total net radiation (TNR). The intermediate and Spanish type cultivars were more stable and productive than the other botanical types of cultivars, commercial varieties exhibited better performance than landraces, and seven cultivars were identified with good production potential, under drought and pluvial conditions. Our study showed that pluvial climate was detrimental to peanut yield, and the SPPW and SPSW were significantly influenced by climates with genotype differences.

探究地区气温、降水等气候资源变化特征,可为气候变化下农业生产规划布局和气象灾害防御提供科学依据.利用1960-2020年海南岛7个气象站逐日气象资料,采用气候倾向率法、Mann-Kendal(MK)检验和Morlet小波分析等方法,对海南岛近61 a气温、降水及参考作物蒸散量(ET0)的时空变化趋势进行了系统分析.结果表明:在时间上,海南岛年平均气温以0.22℃/(10 a)的速率显著上升,年平均降水量以33.66 mm/(10 a)的速率不显著增加,ET0以-0.30 mm/(10 a)的速率轻微下降.MK检验表明气温序列未发生突变,而降水和ET0序列存在突变现象.小波分析表明气温存在55 a的变化主周期,降水和ET0存在56 a的主周期.在不同季节,气温均显著上升,降水和ET0的变化趋势不显著.在空间上,海南岛气温以中部琼中为低值中心向周边沿海地区增加,东南部气温整体高于东北部;降水量以中部琼中为中心向周边沿海地区减小,ET0呈从东北向西南递增的趋势.研究表明近61 a海南岛气候呈现暖湿化趋势,对全球变暖响应显著.预测未来几年气温、降水和ET0将处于偏低期,这将对该地区农业生产和生态系统等产生影响.

以金菠萝(MD-2)为试材,设置不施肥、常规施肥、常规施肥+有机肥、滴灌施肥、滴灌施肥+有机肥等5个不同施肥处理,比较不同处理对其生长、养分吸收、产量和果实品质的影响.结果表明,与常规施肥处理相比,滴灌施肥处理显著提高金菠萝总叶片数、茎高、茎粗、D叶长、D叶宽和果柄粗度;常规施肥处理下,增施有机肥可显著增加茎高和茎粗.滴灌施肥处理的根、茎、叶、果柄和果实干质量均显著高于常规施肥处理,分别增加了 81.72％、303.23％、150.94％、99.61％和86.79％.滴灌施肥、滴灌施肥+有机肥处理的植株氮、磷、钾积累量,果实横径、单果质量和产量均显著高于其他处理.常规施肥处理的果实的维生素C和可滴定酸含量最高,与其他处理差异显著,但该处理糖酸比最低,增施有机肥显著降低了果实可滴定酸含量,提高了糖酸比.

砂仁是姜科豆蔻属多年生草本植物,喜荫湿环境,光照是其生长发育的重要影响因子.为了解砂仁种质材料的光合特性,更好地对砂仁种质资源进行保护和利用.以'湛砂11'的幼苗为材料,农家栽培种'热科1'和'热科2'为对照,使用SPAD-502Plus叶绿素仪、3051D光合仪和WALZ MINI-PAM-Ⅱ叶绿素仪,分别测定叶片的叶绿素含量(SPAD)、净光合速率(Pn)、电子传递速率(ETR)和光合有效量子产量(Y2)等参数,分析'湛砂11'的光合特征和环境适应性.结果表明:'湛砂11'叶片SPAD值为44,比'热科1'高12.47％、比'热科2'低18.59％;叶片净光合速率(Pn)为12.19μmol/(m2·s),分别是'热科1'和'热科2'的1.63倍和5.11倍,极显著高于对照,蒸腾速率(Tr)、气孔导度(Gs)和水分利用效率(WUE)显著高于'热科2'.光合有效辐射在10～1082μmol/(m2·s)条件下,叶片电子传递速率(ETR)随光合有效辐射的增强而上升,'湛砂11'的ETR比'热科1'和'热科2'的高,说明'湛砂11'的PSII具有强的光电子传递能力.因此,'湛砂11'具有较好的光合特性,将光能转化为电子流的能力和潜在光合能力较强,且具有较广的光辐射范围,适宜荫蔽度较低的生长环境.

为探明菠萝田间控水减肥效应及确定补充灌溉施肥水平,为粤西地区菠萝生产中节水节肥和提质增效提供依据.研究以金菠萝'MD-2'为材料,设置无灌溉常规施肥(常规),2个补灌W1(–15～–35 kPa)和W2(–35～–55 kPa)与3个肥料F1(100％)、F2(75％)和F3(50％)梯度处理(F1W1、F2W1、F3W1、F1W2、F2W2、F3W2),以无灌溉无施肥作为对照(CK).研究菠萝光合面积、光合效率、干物质积累、经济性状、灌溉水生产力及肥料偏生产力对不同处理的响应.结果表明,补充灌溉施肥能够显著提高菠萝株高、叶长、叶宽、叶片数和植株干物质含量.水肥限制下,叶片数和叶长的减少是单株叶面积下降的主要因素,而光合面积的减小是干物质量下降的主要因素,菠萝植株生长受限来自于肥料减施和因干旱而导致的肥料利用受限.雨季干旱胁迫解除后叶片实际光化学效率(ΦPSII)能够快速恢复,但营养生长期光合面积显著下降的不可逆转仍然导致果实干物质量和产量显著下降.补充灌溉施肥条件下肥料偏生产力表现为F3>F2>F1,而果实田间产量和田间糖锤度均表现为F3W1,但果实增产率和田间糖锤度在W1和W2之间差异不显著.因此,采用F2W2补充灌溉施肥方式可为菠萝生产中节水节肥和提质增效提供支撑.

为保护和利用陆稻农家种资源,本研究利用SNP标记和表型鉴定对80份陆稻晚稻农家种资源进行遗传多样性综合分析.结果表明:利用水稻1KSNP芯片对80份资源进行检测后共获得739个SNP的基因型数据,基于SNP的群体结构分析、PCA分析和聚类分析,均将80份资源分为云南亚群(63份)、海南亚群(11份)和贵州亚群(6份)共3个亚群,3个亚群间的平均遗传距离分别为0.83、0.63、0.80,其中海南亚群与其他2个亚群的遗传距离较远.贵州的陆稻资源分别属于贵州亚群和云南亚群,表明黔南地区的陆稻资源可能存在不同的来源.云南亚群可进一步分为3个亚群,平均遗传距离分别为0.30、0.28和0.22,表明细分亚群间的遗传距离很近.表型鉴定结果表明,11个表型性状的变异系数在4.09％～38.77％之间,其中有效分蘖数和穗重的变异系数较大,均超过25.00％,株高、种子长、种子宽、种子长宽比和种子圆度均值变异系数较小,均低于10％;遗传多样性指数范围为1.76～2.84,种子长的遗传多样性最丰富.相关分析结果表明,11个表型性状间存在着复杂的相关关系,其中种子长宽比与圆度均值的相关系数最高为0.98.在表型PCA分析中,前5个因子累计贡献率为82.37％,可反映表型性状的绝大部分信息,各成分的贡献率分别为29.08％、23.42％、12.35％、9.77％和7.75％,主要反映了株型和产量相关信息.80份资源的综合得分范围为0.15～0.73,排名前10的种质资源(ZRG36、ZRG101、ZRG58、ZRG31、ZRG1、ZRG102、ZRG104、ZRG63、ZRG29、ZRG11)均来自海拔较高地区,其中2份来源于海南,5份来源于贵州,3份来源于云南,且在穗长、种子长、种子宽、穗重和千粒重表现较好.该研究结果为陆稻农家种资源的保护和利用提供了参考.

季节性干旱是限制菠萝增产提质增效的重要原因,发展"以水促肥,以肥促产,水肥高效耦合"的现代灌溉施肥技术,是应对季节性干旱,促进菠萝增产提质增效的重要途径.本文从华南地区季节性干旱时空分布特征、干旱胁迫对菠萝生长发育的影响、我国菠萝水肥管理现状、灌溉施肥技术对菠萝生长发育的影响等4个方面简要阐述了我国菠萝灌溉施肥技术发展的必要性,重点从现代灌溉施肥方式、耗水规律和养分吸收规律等3方面总结了菠萝灌溉施肥技术研究进展,并结合研究进展提出我国菠萝灌溉施肥技术目前存在的问题,探讨未来可能的研究重点和发展方向,为菠萝灌溉施肥技术的研究与应用提供参考.

Predicting biomass production is important for assessing yield losses caused by drought. Photosynthesis-driven crop growth models, such as SUCROS97, tend to overestimate crop production under severe drought, as they ignore slow post-drought recovery kinetics of leaf photosynthesis. In this study, Lilium plants (L. auratum x speciosum 'Sorbonne') were subjected to mild, intermediate and severe drought with different durations (3, 5, 7 and 9 days) at two developmental stages (leaf unfolding and flower bud break stage). Leaf photosynthesis and chlorophyll fluorescence (CF) were measured during and after drought. We found that at both developmental stages, drought significantly reduced light-saturated gross photosynthesis rate (P-g,P-max), which progressively recovered after re-watering. Under mild drought, P-g,P-max recovered fully to non-stress levels by re-watering, whereas under intermediate and severe drought, P-g,P-max did not recover fully. Drought occurring during leaf unfolding had a larger impact on biomass production than drought during bud break. Further, we identified a sigmoidal relationship (r(2) = 0.81) between P-g,P-max and photosystem II operating efficiency (Phi(2)) during drought, and highly linear relationships (r(2) = 0.88) between P-g,P-max and the quantum yield of non-regulated energy dissipation (FNO) during post-drought recovery. We integrated the aforementioned relationships into SUCROS97, and the extended SUCROS-CF model explicitly accounted for slow and incomplete P-g,P-max recovery in the post-drought phase. Compared to SUCROS97, SUCROS-CF improved biomass prediction by 7%, due to a 19% improvement in P-g,P-max predictions under severe drought. We conclude that to accurately predict productivity during and after severe drought, leaf photosynthetic capacity kinetics need to be considered. Furthermore, CF measurements can be applied to predict leaf photosynthetic capacity during and after drought, enabling rapid drought phenotyping in breeding programs and yield loss assessment in the field.

【Background and objective】 Mulched drip irrigation is often used in dry regions for water-saving, but the mulching film could hinder rainfall infiltration and enhance surface runoff as a result. This could reduce the use of natural rainfall by plants, especially in regions where rainfall is abundant in summer and autumn while scarce in other seasons. The objective of this paper is to evaluate the balance of mulched drip irrigation in saving water in dry seasons and losing water in other seasons due to the increased surface runoff. 【Method】 We took pineapple orchard as an example and conducted the experiment in a field comprising three irrigation treatments: conventional rain-fed cultivation (CK), conventional drip irrigation (DF), and mulched drip irrigation with plastic film (MF). In each treatment, we measured the change in moisture in the 0~100 cm soil profile using FDR sensors. 【Result】 Both conventional and mulched drip irrigation reduced rainfall infiltration in the planting rows. The total rainfall infiltration in the 0~100 cm soil profile on the planting ridge under DF and MF was 48.4% and 60.8% respectively lower than that under conventional rain-fed cultivation, despite that MF did not affect the water use efficiency and fruit yield. Compared with CK, DF and MF increased agronomic productivity of the water by 37.5% and 13.8% respectively, and field biomass by 13.8% and 52.2% respectively. MF also increased rainfall infiltration in the 40~100 cm soil in the burrow between the planted ridges. The rainfall infiltration ratio of moderate rainfall, heavy rainfall and rainstorm was 3.5%, 15.8% and 30.3% for DF, 2.5%, 16.7% and 31.5% for DF, and 15.7%, 39.7% and 43.0% for MF. The wetting depth (accounted for when soil moisture increase was >4%) associated with moderate rainfall, heavy rainfall and rainstorm was 30 cm, 100 cm and 30 cm for CF, 20 cm, 30 cm and 20 cm for DF, and 10 cm, 50 cm and 20 cm for MF. It was found that the mulched drip irrigation stabilized soil moisture in the planting rows; in rainy season, the depth of soil moisture content affected by CK, DF and MF was 0~30 cm, 0~20 cm and 0~10 cm respectively. 【Conclusion】 In regions rich in rainfalls in summer and autumn while dry in other seasons, mulched drip irrigation reduced rainfall infiltration and promoted deep infiltration of rainfall, but it does not affect water agronomic productivity and biomass of the pineapple. It is hence beneficial to saving water and increasing pineapple yield.