 |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Dynamics of Assimilate Translocation and Its Contribution to Maize Kernel Exposed to Different Periods of Water Deficit) ผู้เขียน: M. Robiul Alam,  ดร.สุตเขตต์ นาคะเสถียร, รองศาสตราจารย์ , ดร.เอ็จ สโรบล, ศาสตราจารย์ , ดร.วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractField experiment I was conducted under moderate water deficit conditions at four different growth stages (V10 to V13, V13 to V17, V17 to blister and blister to physiological stage) with three maize genotypes (Pioneer 30B80, NK 40 and Suwan 4452) and field experiment II was conducted under severe water deficit conditions at three stages (V10 to anthesis, anthesis to milk and milk to physiological maturity stage) with two genotypes (NK 40 and Suwan 4452) to evaluate the hypothesis that the translocation of stored stem reserves into the growing grain is an important source of carbon for supporting grain filling under water deficit. Significantly higher assimilate translocation, assimilate translocation efficiency and contribution of pre-anthesis assimilates to the grain were achieved in the V17 to blister stage under moderate water deficit and in the milk to physiological maturity stage under severe water deficit, respectively, with maximum stem dry weight depletion and stem dry weight depletion coefficients. NK 40 always sustained a smaller reduction in grain weight under both experiments. During grain filling, NK 40 exported 43.51 and 28.38% higher stem reserve dry matter compared to Pioneer 30B80 and Suwan 4452 under moderate water deficit conditions and a 46.20% higher stem reserve contribution compared to Suwan 4452 under severe water deficit conditions. Assimilate translocation in the two experiments showed a significant positive relationship with stem dry weight depletion (R2 = 0.81 and 87, respectively) and specific leaf weight depletion (R2 = 0.93 and 88, respectively), whereas it showed a significant negative relationship with the source-sink ratio (R2 = -0.53 and -0.84, respectively) and chlorophyll content (R2 = -0.50 and ?0.63, respectively). |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Responses of Physiological Traits of Maize to Water Deficit Induced at Different Phenological Stages) ผู้เขียน:M. Robiul Alam, ดร.สุตเขตต์ นาคะเสถียร, รองศาสตราจารย์, ดร.เอ็จ สโรบล, ศาสตราจารย์, ดร.วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractTwo field experiments were conducted to evaluate the physiological responses of maize to water deficit conditions. Five water regimes (control, water deficit from V10 to V13, V13 to V17, V17 to blister and blister to physiological maturity) and 3 maize genotypes including Pioneer 30B80, NK 40 and Suwan 4452 were tested under moderate water deficit (MWD). Based on their better physiological performance, NK 40 and Suwan 4452 were further evaluated under severe water deficit (SWD) levels (control, water deficit from V10 to anthesis, anthesis to milk and milk to physiological maturity). The omission of irrigation in the moderate and severe water deficit regimes decreased the soil water potential and resulted in a significant decrease in the relative water content (RWC), chlorophyll content, leaf area (LA) and dry matter (DM) accumulation compared to the control. A greater decrease in the RWC (13.66 and 29.78%) at the V17 and anthesis stages, chlorophyll content (12.75 and 49.44%) at the V17 and late grain filling stages, LA (50.01 and 36.64%) at the V13 and milk stages and DM (15.98 and 14.60%) at the V17 and late grain filling stages was found under moderate and severe water deficit, respectively. The most susceptible stage to MWD and SWD was the V13 to V17 stage and the anthesis to milk stage, respectively in terms of grain yield reduction. After rewatering, the RWC fully recovered or was close to the control level under both water deficits while recovery of chlorophyll was relatively higher in the moderate water stress regime. Rewatering after water deficit at an early stage resulted in a recovery in leaf area but rewatering after anthesis failed to recover leaf area under both experiments. NK 40 demonstrated better performance regarding sustaining a relatively higher RWC and chlorophyll content and a higher yield under both stress environments compared to the other genotypes. The relative water content, chlorophyll content and grain yield showed negative relationships with the available soil water depletion (%), while the grain yield showed a positive relationship with the relative water content and chlorophyll content under both water deficit experiments which can be used as an index for drought screening. |
|
Researcherดร. วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ที่ทำงาน:ภาควิชาพืชไร่นา คณะเกษตร สาขาที่สนใจ:การผลิตพืช และสรีรวิทยาการผลิตพืชไร่, การผลิตและการปรับปรุงพันธุ์มันสําปะหลัง การบริหารและการจัดการ, การจัดการดูแลสนามกอล์ฟ Resume |
|
|