Impact of soil moisture stress during the silk emergence and grain-filling in maize.

Suboptimal soil moisture during the growing season often limits maize growth and yield. However, the growth stage-specific responses of maize to soil moisture regimes have not been thoroughly investigated. This study investigated the response of maize to five different soil moisture regimes, that are, 0.25, 0.20, 0.15, 0.10, and 0.05 m3 m-3 volumetric water content (VWC), during flowering and grain-filling stages. Sub-optimal soil moisture at the flowering and grain-filling stages reduced ear leaf stomatal conductance by 73 and 64%, respectively. An increase in stress severity caused significant reductions in ear leaf chlorophyll content and greenness-associated vegetation indices across growth stages. Fourteen days of soil moisture stress during flowering delayed silk emergence, reduced silk length (19%), and silk fresh weight (34%). Furthermore, sub-optimal soil moisture caused a significant reduction in both kernel number (53%) and weight (54%). Soil moisture stress at the flowering had a direct impact on kernel number and an indirect effect on kernel weight. During grain-filling, disruption of ear leaf physiology resulted in a 34% decrease in kernel weight and a 43% decrease in kernel number. Unlike grain-filling, treatments at the flowering significantly reduced kernel starch (3%) and increased protein by 29%. These findings suggest that developing reproductive stage stress-tolerant hybrids with improved resilience to soil moisture stress could help reduce the yield gap between irrigated and rainfed maize.

Diabetes among Patients with Overt Primary Hypothyroidism Visiting the Outpatient Department of General Medicine of a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: Thyroid diseases are one of the commonest endocrine disorders and hypothyroidism is the commonest among them. There are many publications about hypothyroidism prevalence in diabetes, however, reports of diabetes in hypothyroidism are scarce. This study aimed to find out the prevalence of diabetes among patients with overt primary hypothyroidism visiting the Outpatient Department of General Medicine of a tertiary care centre. Methods: A descriptive cross-sectional study was conducted among adults with overt primary hypothyroidism who attended the Department of General Medicine of a tertiary care centre. Data from 1 November 2020 to 30 September 2021 were collected between 1 December 2021 and 30 December 2021 from the hospital records. Ethical approval was obtained from Institutional Review Committee (Reference number: MDC/DOME/258). Convenience sampling method was used. Out of all patients with different thyroid disorders, consecutive patients with overt primary hypothyroidism were included. The patients with incomplete information were excluded. Point estimate and 95% Confidence Interval were calculated. Results: Among total 520 patients with overt primary hypothyroidism, the prevalence of diabetes was 203 (39.04%) (34.83-43.25, 95% Confidence Interval), with 144 (70.94%) in female and 59 (29.06%) in male. Among 203 hypothyroid patients with diabetes, the proportion of female was more than that of male. Conclusions: The prevalence of diabetes among patients with overt primary hypothyroidism was higher than the other studies done in similar settings. Keywords: diabetes mellitus; hypertension; hypothyroidism; thyroid disorder.

Developing Functional Relationships between Soil Moisture Content and Corn Early-Season Physiology, Growth, and Development.

Drought is a severe threat to agriculture production that affects all growth stages of plants, including corn (Zea mays L.). Any factor affecting early seedling growth and development will significantly impact yield. Despite the recurrence of low rainfall during the growing seasons, corn responses to different early-season soil moisture content levels have not been investigated. In this study, we investigated how corn morpho-physiological and biomass traits responded to varied soil moisture content during the early vegetative stage. Two corn hybrids were grown in a pot-culture facility under five different soil moisture treatments (0.15, 0.12, 0.09, 0.06, and 0.03 m3 m-3 volumetric water content, VWC) to assess the growth and developmental responses to varied soil moisture content during early-season growth (V2 to V7) stage. Sub-optimal soil moisture content limited plant growth and development by reducing physiological and phenotypic expression. Stomatal conductance and transpiration were decreased by an average of 65% and 59% across stress treatments relative to optimum conditions. On average, soil moisture deficit reduced the total leaf area by 71% and 72% compared to the control in 'A6659VT2RIB' and 'P1316YHR', respectively. Shoot and root dry weights were reduced by 74% and 43% under 0.03 m3 m-3 VWC. An increase in the root-to-shoot ratio was noticed under low VWC conditions compared to the control. Based on the stress tolerance index, the physiology and leaf growth parameters were more sensitive to soil moisture deficit. Our results highlight the impact of sub-optimal soil moisture on physiology and morphological traits during early-season growth. 'P1316YHR' demonstrated better physiological performance under stress conditions, while 'A6659VT2RIB' produced relatively better root growth. The findings suggest that biomass partitioning between shoot and root components is dynamic and depends on stress intensity. The current findings can help to prioritize traits associated with the early-season drought tolerance in corn. The functional relationships developed between soil moisture content and growth and developmental responses can be integrated into corn crop modeling to allow better irrigation management decisions.

Resilience of soybean cultivars to drought stress during flowering and early-seed setting stages.

Drought stress during the reproductive stage and declining soybean yield potential raise concerns about yield loss and economic return. In this study, ten cultivars were characterized for 20 traits to identify reproductive stage (R1-R6) drought-tolerant soybean. Drought stress resulted in a marked reduction (17%) in pollen germination. The reduced stomatal conductance coupled with high canopy temperature resulted in reduced seed number (45%) and seed weight (35%). Drought stress followed by rehydration increased the hundred seed weight at the compensation of seed number. Further, soybean oil decreased, protein increased, and cultivars responded differently under drought compared to control. In general, cultivars with high tolerance scores for yield displayed lower tolerance scores for quality content and vice versa. Among ten cultivars, LS5009XS and G4620RX showed maximum stress tolerance scores for seed number and seed weight. The observed variability in leaf reflectance properties and their relationship with physiological or yield components suggested that leaf-level sensing information can be used for differentiating drought-sensitive soybean cultivars from tolerant ones. The study led to the identification of drought-resilient cultivars/promising traits which can be exploited in breeding to develop multi-stress tolerant cultivars.

Effects of drought and heat stresses during reproductive stage on pollen germination, yield, and leaf reflectance properties in maize (Zea mays L.).

Drought and heat stresses are the major abiotic stress factors detrimental to maize (Zea mays L.) production. Much attention has been directed toward plant responses to heat or drought stress. However, maize reproductive stage responses to combined heat and drought remain less explored. Therefore, this study aimed to quantify the impact of optimum daytime (30°C, control) and warmer daytime temperatures (35°C, heat stress) on pollen germination, morpho-physiology, and yield potential using two maize genotypes ("Mo17" and "B73") under contrasting soil moisture content, that is, 100% and 40% irrigation during flowering. Pollen germination of both genotypes decreased under combined stresses (42%), followed by heat stress (30%) and drought stress (19%). Stomatal conductance and transpiration were comparable between control and heat stress but significantly decreased under combined stresses (83% and 72%) and drought stress (52% and 47%) compared with the control. Genotype "Mo17" reduced its green leaf area to minimize the water loss, which appears to be one of the adaptive strategies of "Mo17" under stress conditions. The leaf reflectance of both genotypes varied across treatments. Vegetation indices associated with pigments (chlorophyll index of green, chlorophyll index of red edge, and carotenoid index) and plant health (normalized difference red-edge index) were found to be highly sensitive to drought and combined stressors than heat stress. Combined drought and heat stresses caused a significant reduction in yield and yield components in both Mo17 (49%) and B73 (86%) genotypes. The harvest index of genotype "B73" was extremely low, indicating poor partitioning efficiency. At least when it comes to "B73," the cause of yield reduction appears to be the result of reduced sink number rather than the pollen and source size. To the best of our awareness, this is the first study that showed how the leaf-level spectra, yield, and quality parameters respond to the short duration of independent and combined stresses during flowering in inbred maize. Further studies are required to validate the responses of potential traits involving diverse maize genotypes under field conditions. This study suggests the need to develop maize with improved tolerance to combined stresses to sustain production under increasing temperatures and low rainfall conditions.

Documentation and on farm conservation of neglected and underutilized plant species in Lamjung district, Nepal.

Neglected and underutilized species (NUS) are proven superfoods, but still many of those species are not mainstreamed in our food system. In this regard, research was carried out to explore diversity and identify prioritized species, explore use-values, and identify the role of a socio-demographic factor in its conservation and promotion. For this, a survey was conducted at two rural municipalities' viz. Marsayndi Rural Municipality-01 (Ghanpokhara) and Kwhlosothar Rural Municipality (ward no-03, Ghalegaun & ward no-04, Bhujung) in Lamjung district of Nepal. Location wise cluster sampling was conducted for data collection and the techniques employed were direct field observation, household sampling, key informant interview, personal interviews, and field studies. 92 species were documented during the study, moreover, a significant role of socio-demographic factors was seen in characterizing, evaluating, and conserving NUS on-farm. The results indicated that the education status and primary occupation of the household head had a major role whereas ethnicity had a certain level of the role while gender had no role to play on on-farm conservation of NUS. People with basic education status and agriculture as their primary occupations showed a higher influence on conservation. The result concludes with some insight on the way forward for NUS and addresses a need to establish a research and development program including all potential participants such as with government, academics, entrepreneurs, and producers to promote NUS.