Effect of a mentor-based, supportive-expressive program, Be Resilient to Breast Cancer, on survival in metastatic breast cancer: a randomised, controlled intervention trial.

BACKGROUND: Because of medical advances, metastatic breast cancer (MBC) is now viewed as a chronic disease, rather than an imminent death sentence. Helping women live with this disease requires more than a medical approach to symptoms. Thus, a mentor-based and supportive-expressive program 'Be Resilient to Breast Cancer' (BRBC) was designed to help Chinese women with MBC enhance their resilience levels, biopsychosocial functions, and potentially extend their life span. METHODS: A total of 226 women with MBC were randomly assigned, in a 1 : 1 ratio, to an intervention group (IG) that participated in BRBC or to a control group (CG) that received no intervention. Be Resilient to Breast Cancer was conducted for 120 min once a week. Primary outcomes were cancer-specific survival and secondary outcomes were resilience, Allostatic Load Index (ALI), anxiety, depression, and quality of life (QoL). The Cox proportional-hazards model was used for survival analysis and growth mixture models were performed for secondary outcomes. RESULTS: Be Resilient to Breast Cancer did not significantly prolong 3- or 5-year survival (median survival, 36.7 months in IG and 31.5 months in CG). The hazard ratio for death was 0.736 (95% CI, 0.525-1.133, P=0.076; univariate Cox model) and 0.837 (95% CI, 0.578-1.211, P=0.345; multivariate Cox analysis). The IG improved in anxiety (ES=0.85, P<0.001), depression (ES=0.95, P<0.001), QoL (ES=0.55, P<0.001), resilience (ES=0.67, P<0.001), and ALI (ES=0.90, P<0.001) compared to CG. CONCLUSIONS: BRBC does not improve survival of women with MBC in this study, though longer follow up is warranted. It positively impacts resilience, QoL, ALI, and emotional distress.

Overexpression of folate biosynthesis genes in rice (Oryza sativa L.) and evaluation of their impact on seed folate content.

Folate (vitamin B9) deficiency is a global health problem especially in developing countries where the major staple foods such as rice contain extremely low folates. Biofortification of rice could be an alternative complement way to fight folate deficiency. In this study, we evaluated the availability of the genes in each step of folate biosynthesis pathway for rice folate enhancement in the japonica variety kitaake genetic background. The first enzymes GTP cyclohydrolase I (GTPCHI) and aminodeoxychorismate synthase (ADCS) in the pterin and para-aminobenzoate branches resulted in significant increase in seed folate content, respectively (P < 0.01). Overexpression of two closely related enzymes dihydrofolate synthase (DHFS) and folypolyglutamate synthase (FPGS), which perform the first and further additions of glutamates, produced slightly increase in seed folate content separately. The GTPCHI transgene was combined with each of the other transgenes except ADCS to investigate the effects of gene stacking on seed folate accumulation. Seed folate contents in the gene-stacked plants were higher than the individual low-folate transgenic parents, but lower than the high-folate GTPCHI transgenic lines, pointing to an inadequate supply of para-aminobenzoic acid (PABA) precursor initiated by ADCS in constraining folate overproduction in gene-stacked plants.

Prevalence of cancer-related cognitive impairment among patients with nasopharyngeal carcinoma: a cross-sectional study.

OBJECTIVE: To examine the prevalence of cancer-related cognitive impairment (CRCI) and its contributing factors in patients with nasopharyngeal carcinoma (NPC) and explore the relationship between various assessment methods. METHODS: A cross-sectional study was conducted with 367 patients with NPC between March 2022 and April 2024 at Chongqing University Cancer Hospital. The data gathered from the demographic questionnaire, Montreal Cognitive Assessment (MoCA), Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS) were analyzed using logistic regression. RESULTS: Out of 367 participants, males accounted for 271 (73.84%). There were 217 (59.13%) individuals aged between 35-55 years. Cognitive impairment incidence was 58.04% using MoCA and 47.98% using FACT-Cog. Years of education, work condition, age and time since diagnosis (≥ 11 months) were all significantly associated with cognitive impairment using MoCA, the strongest being time since diagnosis (≥ 11 months) (OR = 2.672, 95% CI = 1.191-5.997, P = 0.017). Gender, marital status (married), place of residence (township), place of residence (city), alcohol history, SAS and SDS were all significantly associated with FACT-Cog, the strongest being marital status (married) (OR = 4.100, 95% CI = 1.130-14.87, P = 0.032). CONCLUSION: Patients diagnosed with NPC exhibit susceptibility to CRCI. There was a weak correlation between some aspects of the subjective tests and the objective test scores. Advanced age and disease diagnosis longer than 10 months are associated with a heightened risk of objective cognitive impairment. Furthermore, residing in rural areas, female, married, alcohol history, SAS and SDS increases the likelihood of subjective cognitive impairment. These findings highlight the need to select appropriate assessment scales for different needs and take targeted interventions to address CRCI in patients with NPC.

Photoinduced remote regioselective radical alkynylation of unactivated C-H bonds.

A method for the remote regioselective alkynylation of unactivated C(sp3)-H bonds in diverse aliphatic amides by photogenerated amidyl radicals has been developed. The site-selectivity is dominated via a 1,5-hydrogen atom transfer (HAT) process of the amide. Mild reaction conditions and high regioselectivity are demonstrated in this methodology.

Photoredox-Catalyzed Difunctionalization of Unactivated Olefins for Synthesizing Lactam-Substituted gem-Difluoroalkenes.

Herein, the synthesis of lactam-substituted gem-difluoroalkenes has been developed through a photoredox-catalyzed radical cascade reaction. This developed photoredox-catalyzed, Brønsted base-assisted intramolecular 5-exo-trig cyclization/intermolecular radical addition/ß-fluoride elimination reaction offers a simple method for producing lactam, carbamate, or urea-substituted gem-difluoroalkenes with good functional group tolerance and high yields.

[Simple nucleus pulposus removal for the treatment of prolapsed and displaced lumbar disc herniation].

OBJECTIVE: To explore the clinical effect of the simple nucleus pulposus removal and small incision interlaminar window in the treatment of prolapsed and displaced lumbar disc herniation. METHODS: From February 2016 to February 2018, 35 patients with single-segment prolapse and displaced lumbar disc herniation were treated by the simple nucleus pulposus removal and small incision interlaminar window under general anesthesia. Among them, there were 21 males and 14 females;aged (42±17) years;27 cases of L4,5 segment, 6 cases of L5S1 segment, 2 cases of L3,4 segment;20 cases on the left side, 13 cases on the right side. Modified Macnab standard was used to evaluate postoperative symptoms and functional recovery. RESULTS: All the operations were successful and the operation time was 30 to 60 min with an average of 40 min, the intraoperative blood loss was 10 to 30 ml with an average of 20 ml. All the patients were followed up for 1 to 3 years with an average of 1.2 years. Thirty-five patients with low back pain and lower limb symptoms were significantly relieved or disappeared. According to modified Macnab standard, 29 cases obtained excellent results, 5 good, and 1 fair. CONCLUSION: Applying the concept of minimally invasive operation, small incision interlaminar window and simple nucleus pulposus removal for the treatment of prolapsed and displaced lumbar disc herniation has the advantages of short operation time, definite curative effect, and less trauma. And it is a safe and effective surgical method under the premise of strict control of the indications.

Remote Regioselective Radical C-H Functionalization of Unactivated C-H Bonds in Amides: The Synthesis of gem-Difluoroalkenes.

The site-selective functionalization of unactivated aliphatic amines is an attractive and challenging synthetic approach. We herein report a general strategy for the remote site-selective functionalization of unactivated C(sp3)-H bonds in amides by photogenerated amidyl radicals to form gem-difluoroalkenes with trifluoromethyl-substituted alkenes. The site selectivity is controlled by a 1,5-hydrogen atom transfer (HAT) process of the amide. This photocatalyzed transformation shows both chemo- and site-selectivity, facilitating the formation of a secondary, tertiary, or quaternary carbon center.

The distribution of japonica rice cultivars in the lower region of the Yangtze River valley is determined by its photoperiod-sensitivity and heading date genotypes.

There are generally four recognized classes of japonica rice cultivars grown in the lower region of the Yangtze River valley. The geographical distribution of the four classes is latitude-dependent. Variation for heading date (HD) among 29 japonica rice cultivars grown in the lower region of the Yangtze River valley and belonging to the four classes was characterized, and their sensitivity to variations in photoperiod and temperature was analyzed. All of the cultivars were sensitive to both photoperiod and temperature. A regression analysis showed that HD is closely correlated with photoperiod sensitivity (PS). The PS of the four classes increased gradually from the medium maturing middle (MMM) types, through the late maturing middle (LMM) and early maturing late (EML) types to the medium maturing late (MML) types. Crosses with tester lines established that almost all of the cultivars carry the dominant early-heading allele at Ef-1, the photoperiod insensitive allele e(2) and the PS alleles E(1) or E(1) (t). Most of the MMM, LMM and MML types carry the insensitive allele e(3), while EML types have either E(3) or E(3) (t). At Se-1, MMM and LMM types have Se-1(e), some EML types have Se-1(e) and others Se-1(n), while the MML types are mostly Se-1(n). The PS of some MMM, LMM and EML types is reduced by the presence of hd2. These results show that the distribution of the four rice cultivar classes from high latitude to low latitude regions depended on a gradual increase in PS, which is mainly determined by its HD genotypes.

[Current status and strategies for improvement of rice grain chalkiness].

This paper reviews the current status of correlation between rice chalkiness and other rice quality characters, formative mechanism, and classical and molecular genetics for rice chalkiness. The formation of rice chalkiness proves to be a complicated physiological process and tightly relate to "source-sink" of rice, dynamics of grain filing, biosynthesis and accumulation of starch in endosperm. Rice chalkiness is a complicated quantitative trait, which is controlled by maternal effects, endosperm effects, and cytoplasmic effects. There are some stable quantitative trait loci (QTL) for rice chalkiness on many rice chromosomes. Of them, three genes controlling rice chalkiness, which have an impact on starch synthesis, starch metabolism, and fruit development, have been cloned. But the manipulative network and formative mechanisms of rice chalkiness remain unclear. At present in breeding practice, decrease of rice chalkiness has become one of the main aims in rice quality breeding, especially for indica rice. The direction of genetic research and improvement strategy of rice chalkiness in future were discussed in this review.

[Efficacy of thunder-fire moxibustion combined with external applicaion of Shuangbai powder for mild and moderate knee osteoarthritis].

OBJECTIVE: To compare the therapeutic effect between thunder-fire moxibustion combined with external applicaion of Shuangbai powder and thunder-fire moxibustion alone for mild and moderate knee osteoarthritis. METHODS: A total of 70 patients with mild and moderate knee osteoarthritis were randomly divided into an observation group and a control group, 35 cases in each group. In the observation group, thunder-fire moxibustion combined with external applicaion of Shuangbai powder were applied, Thunder-fire moxibustion was applied at Xuehai (SP 10), Liangqiu (ST 34), Neixiyan (EX-LE 4), Yanglingquan (GB 34) and ashi point, external applicaion of Shuangbai powder was given to the affected knee after the treatment of thunder-fire moxibustion. Simple thunder-fire moxibustion was given in the control group. All patients in the two groups were treated once a day, 7 days as one course and the consecutive 4 courses were required, with an interval of 1 day between courses. Before and after treatment, the visual analogue scale (VAS) score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were used to assessed knee pain, stiffness and physical function in the two groups. In addition, the efficacy was evaluated. RESULTS: Compared before treatment, the VAS scores, total scores of WOMAC, pain scores, stiffness scores and physical function scores were reduced after treatment in the two groups (P<0.01), and the scores in the observation group were significantly lower than those in the control group (P<0.01, P<0.05). The total effective rate was 97.0% (32/33) in the observation group, which was superior to 91.2% (31/34) in the control group (P<0.05). CONCLUSION: Thunder-fire moxibustion combined with external applicaion of Shuangbai powder are superior to simple thunder-fire moxibustion in improving the symptoms and delaying the development of the disease for mild and moderate knee osteoarthritis.

Observational study on perioperative outcomes of pelvic exenteration / 中华胃肠外科杂志

Objective: To investigate the surgical indications and perioperative clinical outcomes of pelvic exenteration (PE) for locally advanced, recurrent pelvic malignancies and complex pelvic fistulas. Methods: This was a descriptive study.The indications for performing PE were: (1) locally advanced, recurrent pelvic malignancy or complex pelvic fistula diagnosed preoperatively by imaging and pathological examination of a biopsy; (2)preoperative agreement by a multi-disciplinary team that non-surgical and conventional surgical treatment had failed and PE was required; and (3) findings on intraoperative exploration confirming this conclusion.Contraindications to this surgical procedure comprised cardiac and respiratory dysfunction, poor nutritional status,and mental state too poor to tolerate the procedure.Clinical data of 141 patients who met the above criteria, had undergone PE in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to September 2022, had complete perioperative clinical data, and had given written informed consent to the procedure were collected,and the operation,relevant perioperative variables, postoperative pathological findings (curative resection), and early postoperative complications were analyzed. Results: Of the 141 included patients, 43 (30.5%) had primary malignancies, 61 (43.3%) recurrent malignancies, 28 (19.9%) complex fistulas after radical resection of malignancies,and nine (6.4%)complex fistulas caused by benign disease. There were 79 cases (56.0%) of gastrointestinal tumors, 30 cases (21.3%) of reproductive tumors, 16 cases (11.3%) of urinary tumors, and 7 cases (5.0%) of other tumors such mesenchymal tissue tumors. Among the 104 patients with primary and recurrent malignancies, 15 patients with severe complications of pelvic perineum of advanced tumors were planned to undergo palliative PE surgery for symptom relief after preoperative assessment of multidisciplinary team; the other 89 patients were evaluated for radical PE surgery. All surgeries were successfully completed. Total PE was performed on 73 patients (51.8%),anterior PE on 22 (15.6%),and posterior PE in 46 (32.6%). The median operative time was 576 (453,679) minutes, median intraoperative blood loss 500 (200, 1 200) ml, and median hospital stay 17 (13.0,30.5)days.There were no intraoperative deaths. Of the 89 patients evaluated for radical PE surgery, the radical R0 resection was achieved in 64 (71.9%) of them, R1 resection in 23 (25.8%), and R2 resection in two (2.2%). One or more postoperative complications occurred in 85 cases (60.3%), 32 (22.7%)of which were Clavien-Dindo grade III and above.One patient (0.7%)died during the perioperative period. Conclusion: PE is a valid option for treating locally advanced or recurrent pelvic malignancies and complex pelvic fistulas.

Quantitative trait loci mapping of resistance to Laodelphax striatellus (Homoptera: Delphacidae) in rice using recombinant inbred lines.

Laodelphax striatellus Fallén (Homoptera: Delphacidae), is a serious pest in rice, Oryza sativa L., production. A mapping population consisting of 81 recombinant inbred lines (RILs), derived from a cross between japonica' Kinmaze' and indica' DV85' rice, was used to detect quantitative trait loci (QTLs) for the resistance to L. striatellus. Seedbox screening test (SST), antixenosis test, and antibiosis test were used to evaluate the resistance response of the two parents and 81 RILs to L. striatellus at the seedling stage, and composite interval mapping was used for QTL analysis. When the resistance was measured by SST method, two QTLs conferring resistance to L. striatellus were mapped on chromosome 11, namely, Qsbph11a and Qsbph11b, with log of odds scores 2.51 and 4.38, respectively. The two QTLs explained 16.62 and 27.78% of the phenotypic variance in this population, respectively. In total, three QTLs controlling antixenosis against L. striatellus were detected on chromosomes 3, 4, and 11, respectively, accounting for 37.5% of the total phenotypic variance. Two QTLs expressing antibiosis to L. striatellus were mapped on chromosomes 3 and 11, respectively, explaining 25.9% of the total phenotypic variance. The identified QTL located between markers XNpb202 and C1172 on chromosome 11 was detected repeatedly by three different screening methods; therefore, it may be important to confer the resistance to L. striatellus. Once confirmed in other mapping populations, these QTLs should be useful in breeding for resistance to L. striatellus by marker-assisted selection of different resistance genes in rice varieties.

SSR mapping of brown planthopper resistance gene Bph9 in Kaharamana, an Indica rice (Oryza sativa L.).

The brown planthopper (BPH) is one of the most serious insects pests of rice, and the host resistance has been recognized as one of the most economic and effective measures for BPH management. In this study, we conducted a molecular-based genetic analysis of Bph9 in Kaharamana, a Sri Lanka rice variety resistant to BPH insects of East and Southeast Asia. An F2 segregating population composed of 180 plants was constructed from the cross between Kaharamana and 02428, and each F2 plant was self-crossed to obtain F2:3 family. The bulked seedling test method was used to evaluate the resistance of F2:3 families, and the genotype of each F2 plant was inferred from the phenotype of corresponding F2:3 family. Linkage analysis indicated that the resistant gene Bph9 in Kaharamana was located between SSR markers RM463 and RM5341 on chromosome 12 with linkage distances of 6.8 cM and 9.7 cM, respectively. The time- and money-saving SSR markers would be helpful in the application of Bph9 in breeding program via marker-assisted selection.

Mapping and marker-assisted selection of a brown planthopper resistance gene bph2 in rice (Oryza sativa L.).

Nilaparvata lugens Stål (brown planthopper, BPH), is one of the major insect pests of rice (Oryza sativa L.) in the temperate rice-growing region. In this study, ASD7 harboring a BPH resistance gene bph2 was crossed to a susceptible cultivar C418, a japonica restorer line. BPH resistance was evaluated using 134 F2:3 lines derived from the cross between "ASD7" and "C418". SSR assay and linkage analysis were carried out to detect bph2. As a result, the resistant gene bph2 in ASD7 was successfully mapped between RM7102 and RM463 on the long arm of chromosome 12, with distances of 7.6 cM and 7.2 cM, respectively. Meanwhile, both phenotypic selection and marker-assisted selection (MAS) were conducted in the BC1F1 and BC2F1 populations. Selection efficiencies of RM7102 and RM463 were determined to be 89.9% and 91.2%, respectively. It would be very beneficial for BPH resistance improvement by using MAS of this gene.

[Rapid determination of transient expression characteristics of drought- and dehydration-inducible promoters from plants].

The selection of suitable inducible-promoters is one of the most important chains in transgenic researches for plant tolerances to drought, dehydration and other abiotic stresses. Based on laboratory researches in the past years, it was set up a set of methods that could be used to rapidly determine the transient expression characteristics of drought- and dehydration-inducible promoters by using whole barley seedling and plant leaves in vitro as bombardment objects. Promoters Dhn4s, Dhn8s, HVA1s, Rab16Bj and wsi18j isolated from barley and rice were able to express GFP in the leaves of barley, wheat, rice, sorghum and fern after drying treatment, but not in laves of mungbean and tomato. The qualitative expression of HVA1s and wsi18j in different organs and tissues of barley was identified. A method for quantitative analysis of promoter transient expression was established by means of GFP foci/GUS foci counting or GUS activity/XYN activity test. Finally, the value and prospect of the methodology were discussed in terms of its application to the analysis of plant promoters inducible by environmental factors.

Integrative analysis of prognostic long non-coding RNAs with copy number variation in bladder cancer / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Copy number variations (CNVs), which can affect the role of long non-coding RNAs (lncRNAs), are important genetic changes seen in some malignant tumors. We analyzed lncRNAs with CNV to explore the relationship between lncRNAs and prognosis in bladder cancer (BLCA). Messenger RNA (mRNA) expression levels, DNA methylation, and DNA copy number data of 408 BLCA patients were subjected to integrative bioinformatics analysis. Cluster analysis was performed to obtain different subtypes and differently expressed lncRNAs and coding genes. Weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression gene and lncRNA modules. CNV-associated lncRNA data and their influence on cancer prognosis were assessed with Kaplan-Meier survival curve. Multi-omics integration analysis revealed five prognostic lncRNAs with CNV, namely

Mapping of QTLS for ferrous iron toxicity tolerance in rice (Oryza sativa L.).

Ferrous iron toxicity is the main factor limiting the productivity of rice in gleyic paddy soils. In this study, an F2 and an equivalent F3 populations derived from a japonica/indica cross of rice, Longza8503/IR64, were raised under iron-enriched solution cultures, and used to map QTLs controlling ferrous iron toxicity tolerance. A genetic linkage map consisting of 101 SSR markers was constructed to determine the position and nature of quantitative trait loci (QTLs) affecting Fe2+ toxicity tolerance. Three characters, i.e., leaf bronzing index (LBI), plant height (PH) and maximum root length (MRL) were evaluated for the F2 plants and F3 lines and the parents at the seedling stage in nutrient solution. A total of 20 QTLs for LBI, PH and MRL under the Fe2+ stress were detected over 10 of the 12 rice chromosomes, reflecting multigenic control of these traits. QTLs controlling LBI were located at the region of RM315-RM212 on chromosome 1, RM6-RM240 on chromosome 2 and RM252-RM451 on chromosome 4. Compared with other mapping results: (1) the QTL for LBI located at the region of RM252-RM451 on chromosome 4 was identical with the QTL for decreased chlorophyll content on a rice function map. Another QTL for LBI located at the region of RM315-RM212 on chromosome 1 was linked with the QTL for chlorophyll content which located at the region of C178-R2635 on a rice function map. (2) The third QTL for LBI located at the region of RM6-RM240 on choromosome 2 was linked with the QTL for potassium uptake located at the region of RZ58-CDO686 under potassium deficiency stress.

[QTL analysis of low-temperature-sensitive pollen sterility in Indica-japonica hybrid rice (Oryza sativa L.)].

There existed a number of biological constraints in exploiting the heterosis of indica-japonica hybrid rice. The low-temperature-sensitive sterility (LTSS) of indica-japonica hybrid has become one of the major problems in indica-japonica hybrid rice breeding after the solution of poor fertility of the hybrids by the finding of wide-compatibility gene. Previous studies revealed that the LTSS might be caused by low-temperature-sensitive pollen sterility (LTSPS). However, the genetic basis of LTSPS remained unclear. To explore the genetic basis of LTSPS in indica-japonica hybrid rice, an F2 genetic population derived from 3037 (indica) and 02428 (japonica) was developed. At the booting stage, pollen fertility of F2 population together with parents were surveyed after the treatment with low temperature daily average of 21-23 degrees C. The linkage map was constructed containing 108 SSR markers distributed throughout the whole 12 chromosomes with average marker interval of 16.26 cM. Using software MapMaker/QTL, two putative QTLs, namely qLTSPS2 and qLTSPS5 on chromosomes 2 and 5 were detected by interval mapping, which could explain the phenotypic variation 15.6% and 11.9% respectively. The additive effects were 0.021 and 0.045, dominant effects were -0.246 and -0.215, and the degrees of dominance were 11.7 and 4.8, respectively for the two QTLs. Therefore, the mode of gene action in response to low-temperature stress was overdominance and LTSPS was mainly the result of interaction between the indica and japonica alleles within each locus. In addition, two-way ANOVA showed that the two QTLs acted essentially independent of each other in conditioning LTSPS.

[QTL analysis for traits associated with photosynthetic functions in rice (Oryza sativa L.)].

A mapping population of 81 F11 lines (Recombinant Inbred Lines, RILs), derived from a cross between a japonica variety Kinmaze and an indica variety DV85 by single-seed descent method, was used to detect quantitative trait loci (QTL) for traits associated with photosynthetic functions. Total leaf nitrogen content (TLN), chlorophyll a/b ratio (Chl. a:b) and chlorophyll content (Chl) were measured in leaves of rice (Oryza sativa L.) at the 7th day after heading. A total of six putative QTLs were detected with percentage of variance explained (PVE) ranging between 11.2% -29.6%, and LOD of QTLs 2.66-4.81. Of those putative QTLs, three for TLN were detected on chromosomes 1,2 and 11, with PVE of 17.3%, 15.3% and 13.7%, respectively;Two controlling Chl. a:b on chromosomes 3 and 4, PVE of 13.8% and 29.6%, one for Chl on chromosome 1, PVE of 11.2%. Four of those detected QTLs were newly reported in this study. Interestingly, the QTL controlling chlorophyll content,namely qCC-1 reported here,was detected in the region of the RFLP marker C122 on chromosome 1, where harbored NADH-glutamate synthase structure gene according to a previous study. Because the biosynthesis of chlorophyll begins with glutamate, qCC-1 would play a vital role in photosynthetic functions. Whereas,no QTL controlling chlorophyll content were detected at the 30th day after heading, suggesting that the effect of the QTL controlling chlorophyll content decreased during leaf senescence.